Structures and components thereof

ABSTRACT

The application relates to various improvements to elements, structures, and components of structures used to support lighting, scenic, and other loads, including, but not limited to, those suitable for entertainment and display applications. Improved profiles for elongated structural shapes used for and used in structures for such purposes are disclosed, as well as improved fittings for connecting such shapes with each other; with supporting structures; and for connecting loads to them. Improvements are disclosed to methods of supporting structures, and for fabricating and interconnecting them.

[0001] This application relates structures and components thereof suchas are used in connection with lighting and other equipment.

BRIEF SUMMARY OF THE INVENTION

[0002] The application discloses a variety of improvements to structuresand components thereof such as are used in connection with lighting andother equipment.

BRIEF DESCRIPTION OF THE DRAWINGS

[0003]FIG. 1A is a cross section of the prior art circular pipe andtubing widely employed.

[0004]FIG. 1B is a cross section of the prior art square tubing as hasbeen employed.

[0005]FIG. 1C is a cross section of the prior art square tubing withrounded corners that has been employed.

[0006]FIG. 1D is a cross section of the prior art “unistrut” track thathas been employed.

[0007]FIG. 1E is a cross section of the prior art extruded tubing havingan integral “unistrut” track as has been employed.

[0008]FIG. 1F is a cross section of tubing having a circular externalprofile but varying wall thickness to increase its strength/stiffness incertain orientations.

[0009]FIG. 1G is a cross section of tubing having a generally octagonalexternal profile with rounded corners.

[0010]FIG. 1H is a cross section of tubing having a similar octagonalprofile to that of the tubing of FIG. 1G with the addition of thevarying wall thickness of the tubing of FIG. 1F

[0011]FIG. 1I is a cross section of tubing having an internal web toincrease strength/stiffness.

[0012]FIG. 1J is a cross section of tubing having an internal structureto increase its strength/stiffness.

[0013]FIG. 1K is a cross section of tubing having an internal web andvarying wall thickness to increase its- strength/stiffness.

[0014]FIG. 1L is a cross section of tubing having internal ribs thatincrease its strength/stiffness.

[0015]FIG. 1M is a cross section of tubing having both another externalprofile and having internal ribs.

[0016]FIG. 1N is a cross section of tubing having internal ribs andillustrating how another element can be inserted in it and fixed inplace.

[0017]FIG. 1O is a cross section of tubing having the internal profileof the tubing of FIG. 1L with a different external profile.

[0018]FIG. 1P is a cross section of tubing having the internal profileof the tubing of FIG. 1N and the external profile of FIG. 1Qillustrating another element inserted in it.

[0019]FIG. 1Q is a cross section of tubing having alternative externaland internal profiles and illustrating another element inserted in it.

[0020]FIG. 1R is a cross section of tubing having internal ribs and websfor stiffening.

[0021]FIG. 1S is a cross section of tubing having internal webs forstiffening.

[0022]FIG. 1T is a cross section of tubing having internal webs forstiffening and showing the insertion of an additional element.

[0023]FIG. 1U is a cross section of tubing having internal webs forstiffening and providing a “unistrut” type feature.

[0024]FIG. 1V is a cross section of tubing having a large recess.

[0025]FIG. 1W is a cross section of tubing having a plurality ofrecesses that provide for stiffening and accept a “key” that preventsrotation.

[0026]FIG. 2A is a side elevation of a “cheseboro” type clampillustrating one possible interior profile that prevents rotation of atube that employs a suitable exterior profile as illustrated in many ofthe prior Figures.

[0027]FIG. 2B is a side elevation of a “cheseboro” type clamp having aninterior profile similar to that of the clamp of FIG. 2A illustratingits use with conventional tubing and certain other features.

[0028]FIG. 2C is a detail of the side elevation of the prior Figuresshowing one possible interior profile.

[0029]FIG. 2D is a cross section of a structural shape accepting tubingand having many applications.

[0030]FIG. 2E is a cross section of a structural shape like that of FIG.2D but having a continuously open slot at least at the cutting plane.

[0031]FIG. 2F is a cross section of a structural shape like that ofFIGS. 2D and 2E, illustrating the use of a bolt and nut plate for fixingthe tubing in place.

[0032]FIG. 2G is a cross section of a structural shape like that of theprior Figures with the addition of an internal profile similar inprinciple to that of FIGS. 2A-2C, that both accepts conventional tubingand prevents the rotation of tubing having a suitable exterior profile,here illustrated with a conventional tube.

[0033]FIG. 2H is a cross section of the structural shape of FIG. 2G,shown with tubing having an anti-rotation feature.

[0034]FIG. 2I is a cross section of the structural shape of the priorFigures in which the nut plate slot incorporates a “unistrut” typedetail.

[0035]FIG. 2J is a cross section of the structural shape of the priorFigures and incorporating an external flange.

[0036]FIG. 2K is a cross section of the structural shape of the priorFigures having provisions on its exterior for attachment to otherobjects.

[0037]FIG. 2L is a cross section of the structural shape of FIG. 2Jshowing another structural shape welded to it.

[0038]FIG. 2M is a cross section of the structural shape of FIG. 2Jillustrating the use of an interlocking structural shape.

[0039]FIG. 2N is a cross section of the structural shape of the priorFigures illustrating flanges large enough to permit bolted and similarmechanical connections.

[0040]FIG. 2O is a side elevation of a section of the structural shapeof FIG. 2N attached to a tube.

[0041]FIG. 2P is a plan or top view of FIG. 2O.

[0042]FIG. 2P is a side elevation equivalent to FIG. 2O with theaddition of a second such section bolted to the first to form a rigidright-angle fitting.

[0043]FIG. 2R is a section through an assembly including two structuralshapes welded to an intermediate member and used to maintain two tubesin a parallel relationship.

[0044]FIG. 2S is a side elevation of an assembly as illustrated in theprior Figure.

[0045]FIG. 2T is a section through an assembly including two structuralshapes interconnected by interlocking intermediate structural shapes andused to maintain two tubes in a parallel relationship.

[0046]FIG. 2U is a side elevation of an assembly as illustrated in theprior Figure.

[0047]FIG. 2V is a section through an assembly including two structuralshapes joined by an intermediate member and used to maintain two tubesin a parallel relationship.

[0048]FIG. 2W is a side elevation of an assembly as illustrated in theprior Figure.

[0049]FIG. 3A is a cross section of a paired shape having advantages inthe support of fixtures and other loads.

[0050]FIG. 3B is a top view of the paired shape of FIG. 3A.

[0051]FIG. 3C is a cross section illustrating one application of thepaired shape of FIG. 3A, showing the use of a bolt whose head isaccommodated in the profile of the paired shape.

[0052]FIG. 3D is a top view of the application illustrated in FIG. 3C.

[0053]FIG. 3E is a cross section illustrating a second application ofthe paired shape of FIG. 3A, showing the use of a nut accommodated inthe profile of the paired shape.

[0054]FIG. 3F is a top view of the application illustrated in FIG. 3E.

[0055]FIG. 3G is a cross section illustrating one application of thepaired shape of FIG. 3A, showing the use of a bolt whose cap-style headis accommodated in the profile of the paired shapes.

[0056]FIG. 3H is a top view of the application illustrated in FIG. 3G.

[0057]FIG. 3I is a cross section illustrating the use of a fastener witha head narrow enough in one dimension to permit its insertion fromeither side of the paired shapes.

[0058]FIG. 3J is a top view of the application illustrated in FIG. 3!.

[0059]FIG. 3K is a cross section illustrating the insertion of a spacerplug between the paired shape illustrated in the prior Figures.

[0060]FIG. 3L is a top view of the spacer plug illustrated in FIG. 3K.

[0061]FIG. 3M is a cross section illustrating another embodiment ofpaired shapes, which accepts an interlocking place.

[0062]FIG. 3N is a top view of the application of FIG. 3M.

[0063]FIG. 3O is a cross section illustrating the paired shapes of FIG.3M in use.

[0064]FIG. 3Q is a cross section illustrating a plug shape that can beused with the paired shapes of FIG. 3M.

[0065]FIG. 3QQ is a detail view from the same perspective as FIG. 3Q,showing the plug shape in isolation.

[0066]FIG. 3R is another embodiment of paired shapes, which accept twointerlocking plates.

[0067]FIG. 3S is a cross section illustrating the paired shapes andinterlocking plates of FIG. 3R in use.

[0068]FIG. 3T is another embodiment of paired shapes.

[0069]FIG. 3U is a plug shape that can be used with the paired shapes ofFIG. 3T.

[0070]FIG. 3V is a cross section illustrating one method of supportingtwo paired shapes in the required relationship.

[0071]FIG. 3W is a bottom view of the arrangement of FIG. 3V.

[0072]FIG. 3X is a cross section illustrating another method ofsupporting paired shapes.

[0073]FIG. 3XX is a detail view from the same perspective as FIG. 3Xshowing the view of another embodiment of a paired shapes, showing thesupport in isolation.

[0074]FIG. 3Y is a cross section illustrating a support useable with thepaired shapes illustrated in FIG. 3T.

[0075]FIG. 4A is an elevation of one end of a typical 12″×12″ truss.

[0076]FIG. 4B is an elevation of one end of a typical “20.5″” truss.

[0077]FIG. 4C is an elevation of one end of one embodiment of animproved truss in one orientation.

[0078]FIG. 4D is an elevation of one end of an embodiment of an improvedtruss in another orientation.

[0079]FIG. 4E is an elevation of a pair of the embodiment of the priorFigures in one orientation.

[0080]FIG. 4F is an elevation of a pair of the embodiment of the priorFigures in another orientation.

[0081]FIG. 4G is an elevation of a trio of the embodiment of the priorFigures in one orientation.

[0082]FIG. 4H is an elevation of one short side of the embodiment of theprior Figures.

[0083]FIG. 4I is an elevation of one long side of the embodiment of theprior Figures.

[0084]FIG. 4J is an elevation of the other short side of the embodimentof the prior Figures.

[0085]FIG. 4K is an elevation of the other long side of the embodimentof the prior Figures.

[0086]FIG. 4L is a detail view of one end of the embodiment of the priorFigures from the same perspective as FIG. 4I.

[0087]FIG. 4M is a cross section through the end of one embodiment ofthe prior Figures on a cutting plane illustrated in FIG. 4L, lookingtowards the short side.

[0088]FIG. 4K is a cross section through the end of one embodiment ofthe prior Figures on a cutting plane illustrated in FIG. 4L, lookingtowards the truss section end.

[0089]FIG. 4O is an elevation of one end of the embodiment of the priorFigures from the perspective identified in FIG. 4L, showing additionaldetail.

[0090]FIG. 4P is a section through one major chord of a truss or otherstructure illustrating the geometry of the intersection of the majorchord and a cross brace.

[0091]FIG. 4Q is an oblique view of the intersection of the major chordand a cross brace as illustrated in FIG. 4P.

[0092]FIG. 4R is a cross section through the structural shape used forthe cross braces of the prior two Figures.

[0093]FIG. 4S is a section through a structural shape that may be usedas one major chord of a truss or other structure illustrating thegeometry of its intersection with another structural shape.

[0094]FIG. 4T is an oblique side view of the intersection of the twostructural shapes illustrated in FIG. 4S.

[0095]FIG. 4U is an oblique top view of the intersection of the twostructural shapes illustrated in FIG. 4S.

[0096]FIG. 4V is a cross section through the another structural shape ofthe prior three Figures.

[0097]FIG. 4W is an oblique view of one end of a length of structuralshape with internal reinforcement.

[0098]FIG. 4X is a cross section through the structural shapeillustrated in FIG. 4W, showing the reinforcement.

[0099]FIG. 4Y is a detail of a cross section through the structuralshape and reinforcement of the prior Figures at the location of a passhole.

[0100]FIG. 4Z is a detail of a cross section like the prior Figuresillustrating the use of a stack of thin plates to form thereinforcement.

[0101]FIG. 5A is a cross section through a pair of truss sections orother structures illustrating the use of a bolted connection betweenthem.

[0102]FIG. 5B is a similar view to FIG. 5A with the addition of bracketscaptivating the female threaded fasteners.

[0103]FIG. 5C is an oblique view of the subject matter of FIG. 5Bshowing the use of a common bracket to captivate a plurality of threadedfemale fasteners.

[0104]FIG. 5D is a similar view to FIG. 5B with the addition of bracketsfor captivating washers on the bolt side of the connections.

[0105]FIG. 5E is a similar view to FIG. 5B in which the means tocaptivate the female threaded fastener is made integral with the trussstructure.

[0106]FIG. 5F is an elevation of a female threaded insert suitable foremployment with the captivating method illustrated in FIG. 5E.

[0107]FIG. 5G is a side elevation of the threaded insert illustrated inFIG. 5F.

[0108]FIG. 5H is a top view of the threaded insert illustrated in FIGS.5F and 5G.

[0109]FIG. 5I is an elevation of the truss structure with thecaptivating method illustrated in FIG. 5E.

[0110]FIG. 5J is the same elevation as FIG. 5I with the addition of thethreaded insert illustrated in FIG. 5F-5H.

[0111]FIG. 5K is a cross section through the truss end in a verticalplane having the same subject matter as FIG. 5J.

[0112]FIG. 5L is the same elevation of the truss end as FIG. 5Jillustrating another method of aligning the threaded insert.

[0113]FIG. 5M is the same cross section of the truss end as FIG. 5Killustrating the another method of aligning the threaded insert alsoillustrated in FIG. 5L.

[0114]FIG. 5N is a cross section similar to FIG. 5E illustrating meansto captivate hardware on both sides of a connection.

[0115]FIG. 5O is an elevation of an insert suitable for use in thepreviously illustrated truss ends that includes both threaded andunthreaded holes.

[0116]FIG. 5P is a side elevation of the insert illustrated in FIG. 5O.

[0117]FIG. 5Q is a top view of the insert illustrated in FIGS. 5O and5P.

[0118]FIG. 5R is an oblique view of the subject matter of FIG. 5Nillustrating the use of the insert illustrated in FIGS. 5O-5Q in twoversions, one including a plurality of both threaded and unthreadedholes.

[0119]FIG. 5S is a cross section through a vertical plane equivalent inperspective to FIGS. 5K and 5M, but through the structure on both sidesof a connection, and showing the insert illustrated in FIGS. 5O-5Q inuse.

[0120]FIG. 5T is a top view of a male and a female clevis fitting as maybe employed in joining trusses and other structures.

[0121]FIG. 5U is a side view of a male and a female clevis fitting asillustrated in the prior Figure, FIG. 5T.

[0122]FIG. 5V is a side elevation of the ends of two sections of truss,illustrating the male and female clevis fittings of the prior FIGS. 5Tand 5U installed in the truss ends.

[0123]FIG. 5W is a top view of the ends of two truss sections of truss,illustrating a joining “tang” installed on one side of the trussconnection.

[0124]FIG. 5X is a side elevation of the joining tang illustrated in theprior FIG. 5W seen in isolation.

[0125]FIG. 5Y is an end elevation of the joining tang as illustrated inprior FIGS. 5W and 5X seen in isolation.

[0126]FIG. 5Z is a side elevation of the subject matter of FIG. 5W.

[0127]FIG. 6A is an elevation of one side of a unit that may be used tointerconnect truss sections and for other purposes.

[0128]FIG. 6B is a detail of one hole pattern that may be employed in aunit like that illustrated in the prior FIG. 6A.

[0129]FIG. 6C is a detail of a hole pattern similar to that illustratedin prior FIG. 6B, but having additional holes to permit use withadditional truss types.

[0130]FIG. 6D is a cross section through a unit like that illustrated inFIG. 6A and other Figures.

[0131]FIG. 6E is a cross section through one of the possible embodimentsof a structural shape that can be used at the corners of a unit likethat illustrated in the prior FIGS. 6A and 6D.

[0132]FIG. 6F is a cross section through another embodiment of astructural shape like that in the prior Figures.

[0133]FIG. 6G is a cross section through another embodiment of astructural shape like that in the prior Figures.

[0134]FIG. 6H is a side elevation of a unit that may be used tointerconnect trusses and for other purposes and including features likecasters and a stacking interlock detail.

[0135]FIG. 6I is a side elevation of a unit that may be used tointerconnect trusses and for other purposes and including the featuresillustrated in the prior FIG. 6H and a handle detail.

[0136]FIG. 6J is a side elevation illustrating a unit such asillustrated in the prior Figures used to join trusses and suspended by achain motor.

[0137]FIG. 6K is a cross section through a structural shape suitable foruse at the corners of a unit having sides of different widths.

[0138]FIG. 6L is a cross section through a unit like that illustrated inFIGS. 6H and 6I, said cross section through a vertical plane andillustrating various features including structural shapes for the topand bottom edges of the unit and the casters and interlocking stackingdetail.

[0139]FIG. 6M is a cross section through one structural shape suitablefor uses including the top edge of the unit illustrated in cross sectionin FIG. 6L.

[0140]FIG. 6N is a cross section through another structural shapesuitable for uses including the top edge of the unit illustrated incross section in FIG. 6L.

[0141]FIG. 6O is a cross section through another structural shapesuitable for uses including the top edge of the unit illustrated incross section in FIG. 6L.

[0142]FIG. 6P is a cross section through one structural shape suitablefor uses including the bottom edge of the unit illustrated in crosssection in FIG. 6L.

[0143]FIG. 6Q is a cross section through another structural shapesuitable for uses including the bottom edge of the unit illustrated incross section in FIG. 6L.

[0144]FIG. 6R is a cross section through one structural shape suitablefor uses including the bottom edge of the unit illustrated in crosssection in FIG. 6L.

[0145]FIG. 6S is a cross section illustrating the adjacent top andbottom chords of two stacked truss sections.

[0146]FIG. 6T is a cross section of a unit having the interlockingstacking detail and caster arrangement illustrated in the prior Figures,including FIG. 6L. stacked atop a truss section.

[0147]FIG. 6U is a cross section illustrating two units having thefeatures illustrated in the prior Figures including FIG. 6L stacked oneatop the other.

[0148]FIG. 6V is a section through a handle detail such as illustratedin FIG. 6I.

[0149]FIG. 6W is a section through a handle detail as illustrated in theprior FIG. 6V with an adapter used to permit a threaded structuralconnection in the area occupied by the handle detail.

[0150]FIG. 6X is a side elevation illustrating the use of an adapter topermit the use of a unit with a truss section or other element having alarger size.

[0151]FIG. 7A is a side elevation of a unit equivalent to the view inFIG. 6I with the addition of provisions to insert tubing into the unit.

[0152]FIG. 7B is a cross section through a structural shape suitable foruses including at the bottom edge of the unit illustrated in the priorFIG. 7A and having provisions to accept and retain tubing.

[0153]FIG. 7C is a cross section through another structural shapesuitable for uses including at the bottom edge of the unit illustratedin the prior FIG. 7A and having provisions to accept a tube and aflange.

[0154]FIG. 7D is a cross section through another structural shapesuitable for uses including at the bottom edge of the unit illustratedin the prior FIG. 7A, having provisions to accept a tube, andillustrating a wire rope loop around its circular portion.

[0155]FIG. 7E is a cross section through another structural shapesuitable for uses including at the bottom edge of the unit illustratedin the prior FIG. 7A, having provisions to accept a tube, and toaccommodate various fittings.

[0156]FIG. 7F is a cross section of the same structural shapeillustrated in FIG. 7E with a fitting suitable for fixing the tube inplace.

[0157]FIG. 7G is a side elevation of the fitting illustrated in priorFIG. 7F.

[0158]FIG. 7H is an end elevation of the fitting seen in the prior twoFigures.

[0159]FIG. 7I is a cross section of the same structural shapeillustrated in FIG. 7E with a fitting suitable for use in suspending theunit.

[0160]FIG. 7J is a cross section of the same structural shapeillustrated in FIG. 7E with another fitting suitable for use insuspending the unit.

[0161]FIG. 7K is a side elevation of the fitting illustrated in priorFIG. 7J.

[0162]FIG. 7I is a cross section through the fitting seen in the priortwo Figures.

[0163]FIG. 7M is an oblique view of the subject matter of FIG. 7J.

[0164]FIG. 7N is an end elevation of a bracket that may be used to clampa tube parallel to a side of the illustrated unit.

[0165]FIG. 7O is a side elevation of the bracket illustrated in theprior FIG. 7N.

[0166]FIG. 7P is an end view of the bracket illustrated in the prior twoFigures in use.

[0167]FIG. 7Q is a side view of the bracket illustrated in the priorFIGS. 7N and 7O in use.

[0168]FIG. 7R is a cross section of a structural shape suitable to clampa tube to a surface such as a side of the unit illustrated.

[0169]FIG. 7S is a side elevation of the structural shape illustrated inthe prior FIG. 7R in a short length.

[0170]FIG. 7T is a side elevation of the structural shape illustrated inthe prior FIG. 7R in an extended length.

[0171]FIG. 7U is a cross section of another structural shape suitable toattach a tube to a surface.

[0172]FIG. 7V is a cross section of another structural shape suitable toattach a tube to a surface.

[0173]FIG. 7W is an elevation of structural shapes like thoseillustrated in the prior Figures in use.

[0174]FIG. 7X is an elevation from another side of structural shapeslike those illustrated in the prior Figures in use.

[0175]FIG. 8A is one elevation of a structure assembled from a pluralityof units, tubes, and structural shapes as illustrated in prior Figures,seen from a perspective identified in FIG. 8C.

[0176]FIG. 8B is another elevation of a structure assembled from aplurality of units, tubes, and structural shapes as illustrated in priorFigures, seen from a perspective identified in FIG. 8C.

[0177]FIG. 8C is a plan view of a structure assembled from a pluralityof units, tubes, and structural shapes as illustrated in prior Figures,elevations of which appear as FIGS. 8A and 8B.

[0178]FIG. 8D is one elevation of a structure assembled from a pluralityof units, truss sections, tubes, and structural shapes as illustrated inprior Figures, seen from a perspective identified in FIG. 8F.

[0179]FIG. 8E is another elevation of a structure assembled from aplurality of units, truss sections, tubes, and structural shapes asillustrated in prior Figures, seen from a perspective identified in FIG.8F.

[0180]FIG. 8F is a plan view of a structure assembled from a pluralityof units, truss sections, tubes, and structural shapes as illustrated inprior Figures, elevations of which appear as FIGS. 8D and 8E.

[0181]FIG. 8G is one elevation of a structure assembled from a pluralityof units, truss sections, tubes, and structural shapes as illustrated inprior Figures, and provided with means permitting a plurality of suchstructures to be stacked.

[0182]FIG. 8H is another elevation of a structure assembled from aplurality of units, truss sections, tubes, and structural shapes asillustrated in prior Figures, and provided with means permitting aplurality of such structures to be stacked.

[0183]FIG. 8I is a detailed view of the stacking detail from the sameperspective as FIG. 8G.

[0184]FIG. 8J is a detailed view of the stacking detail from the sameperspective as FIG. 8G.

[0185]FIG. 8K is an elevation showing the use of a planar element tomaintain the spacial relationship between a unit and another element.

[0186]FIG. 8L is a plan view of the subject matter of FIG. 8L.

[0187]FIG. 8M is an elevation showing the use of elongated structuralshapes to maintain the spacial relationship between a unit and anotherelement.

[0188]FIG. 8N is an elevation illustrating three larger units stackedfor storage and/or transport.

[0189]FIG. 8O is an elevation of the same subject matter as the priorFigure illustrating the attachment of lifting means.

[0190]FIG. 8P is an elevation of the same subject matter as the priorFigure illustrating the top larger unit being lifted.

[0191]FIG. 8Q is an elevation of the same subject matter as the priorFigure illustrating all but the bottom larger unit being lifted.

[0192]FIG. 8R is a side elevation of one design for a unit from whichlarger units can be assembled.

[0193]FIG. 8RR is a detailed view from the prior Figure.

[0194]FIG. 8S is a section through the unit of the prior Figures in aplane parallel to that of the prior Figures.

[0195]FIG. 8T is a plan or top view of the portion of the unit seen inFIG. 8RR.

[0196]FIG. 8U is an elevation of the end of the unit.

[0197]FIG. 8V is a section through the unit at right angles to thesection of FIG. 8S

[0198]FIG. 9A is a side elevation of a wheel bracket.

[0199]FIG. 9B is a side elevation of a wheel structure in the process ofbeing attached or detached from the chords of a truss.

[0200]FIG. 9C is a section through a wheel bracket from the sameperspective as the prior two Figures.

[0201]FIG. 9D is a side elevation of the wheel bracket attached to thechords of one truss which is stacked on a second.

[0202]FIG. 9E is an end elevation of the wheel bracket illustrated inthe prior Figures.

[0203]FIG. 9F is an end elevation of the central member used in thewheel bracket illustrated in the prior Figures.

[0204]FIG. 9G is an exploded end elevation of one alternative approachto the construction of the central member of the wheel bracket.

[0205]FIG. 9H is an end elevation of a wheel bracket with the additionof a feature that engages a cross brace in the truss sections with whichit is used.

[0206]FIG. 9I is a detailed view of the latching mechanism used in theembodiment of the wheel bracket illustrated in the previous Figures.

[0207]FIG. 9J is an embodiment of a wheel bracket whose central memberis designed to accommodate “compound” trusses as illustrated in FIG. 4E.

[0208]FIG. 9K is an,embodiment of a wheel bracket that can be adjustedto different chord spacings.

[0209]FIG. 9L illustrates an embodiment that permits suspending thetruss a bracket also serving as a wheel bracket.

[0210]FIG. 9M is an end elevation of the prior Figure.

[0211]FIG. 9N is a side elevation of another embodiment of a wheelbracket.

[0212]FIG. 9O is an end elevation of the embodiment of the priorFigures.

[0213]FIG. 9P is a side elevation of an embodiment that supports a chainmotor inside the truss.

[0214]FIG. 9Q is an end elevation of the embodiment of the prior Figure.

[0215]FIG. 9R is a section through a soft structure accommodating achain motor in a truss.

[0216]FIG. 9S is plan view of the subject matter of the prior Figure.

[0217]FIG. 9T is a section through another embodiment of a structuresupporting a chain motor inside a truss.

[0218]FIG. 9U is a top or plan view of the subject matter of the priorFigure.

[0219]FIG. 9V is a side elevation of the subject matter of the priorFigures.

[0220]FIG. 9X is a side elevation of a “stacker” in use with two trusssections.

[0221]FIG. 9XX is a detail view from the same perspective as FIG. 9X.

[0222]FIG. 9Y is a section through the “stacker” illustrated in theprior two Figures in use.

[0223]FIG. 9Z is a partial plan view of the “stacker” illustrated in theprior Figures in use.

[0224]FIG. 10A is a cross section through a unit showing a chain motor“flown” above it.

[0225]FIG. 10B is a cross section through a unit showing the chain motorengaged to it.

[0226]FIG. 10C is a side elevation of the subject matter of FIG. 10B.

[0227]FIG. 10D is a cross section through a unit with a chain motorengaged to it and a truss suspended below it.

[0228]FIG. 10E is a side elevation of the subject matter of FIG. 10D.

[0229]FIG. 10F is a cross section through a unit suspended below a chainmotor.

[0230]FIG. 10G is a side elevation of the subject matter of FIG. 10F.

[0231]FIG. 10H is a cross section through a unit illustrating oneembodiment of a bracket to which a chain motor can be attached.

[0232]FIG. 10I is a cross section through a unit perpendicular to theview of the prior FIG. 10H.

[0233]FIG. 10J is a section through a unit with a bracket of anotherdesign.

[0234]FIG. 10K is a detail from the same perspective as the view of FIG.10H of a detail that permits relocating the bracket along an axisperpendicular to the plane of the Figure.

[0235]FIG. 10L is a cross section of a unit showing a chain motor with aplate attached that can connect the chain motor to the unit and/or aload.

[0236]FIG. 10M is a cross section through the unit showing the plateattached to the chain motor to the unit by means of brackets attached tothe unit.

[0237]FIG. 10N is a cross section through the unit showing dividers thatrestrict undesirable motion of the chain motor during shipping of themotor in the unit.

[0238]FIG. 10O is a cross section through the unit with dividersillustrated in the prior FIG. 10O, in a view perpendicular to the priorFigure.

[0239]FIG. 10P is a cross section through a unit showing one design fora lid.

[0240]FIG. 10PP is a detail of the lid of FIG. 10P, seen in isolation.

[0241]FIG. 10Q is a cross section through a unit showing another designfor a lid.

[0242]FIG. 10R is a cross section through a unit showing another designfor a lid.

[0243]FIG. 11A is a side elevation of an assembly for supporting trusssections with loads hung from them.

[0244]FIG. 11B is an end elevation of the assembly of the prior Figure.

[0245]FIG. 11C is the same view as the prior Figure with the wheelassembly retracted for use.

[0246]FIG. 11D to a plan or top view of the subject matter of the priorFigures.

[0247]FIG. 11E, is a side elevation from the same perspective as FIG.11A but a wider view.

[0248]FIG. 11F is a top view of an alternate design for the assembly.

[0249]FIG. 11G is an end elevation of an alternate approach to casterattachment.

[0250]FIG. 11H is a top or plan view of another alternate design for theassembly.

[0251]FIG. 11I is a side elevation of the alternate design of the priorFigure.

[0252]FIG. 11J is an end elevation of an alternate design thatincorporates a stacking feature.

[0253]FIG. 11K is an end elevation showing the accommodation of suchtrusses in a truck.

[0254]FIG. 11L is a section through a truss illustrating an alternativedesign that permits attachment at other points along the truss.

[0255]FIG. 11M is a plan or top view of the alternative design of theprior Figure.

[0256]FIG. 11N is a side elevation of a bracket that supports a chainmotor above a truss.

[0257]FIG. 11O is an end view of the bracket of the prior Figure.

[0258]FIG. 11P is a side elevation of a bracket that stacks two trusseswhile allowing space for the chain motor bracket of the prior Figuresinbetween.

[0259]FIG. 11Q is an end elevation of the stacking bracket of the priorFigure.

[0260]FIG. 11R is a side elevation of the brackets of the prior Figuresin use.

[0261]FIG. 11S is an end elevation showing the brackets of the priorview in use in the truck.

[0262]FIG. 11T is an end elevation of an alternative design that permitsstacking pre-hung trusses.

[0263]FIG. 11U is an elevation of a spacer plate that supports a secondtruss above the first.

[0264]FIG. 11V is a section of an extruded hinge used in a truss havinga pivoting side in one position.

[0265]FIG. 11W is a section of an extruded hinge used in a truss havinga pivoting side in a second position.

[0266]FIG. 11X is a section of an extruded hinge showing a plug shape.

[0267]FIG. 12A is a side elevation of a stacked rotator assembly.

[0268]FIG. 12B is a top view of the upper layer of the rotator assembly.

[0269]FIG. 12C is a top view of the upper portion of the rotator ring.

[0270]FIG. 12D is a top view of the lifting layer with the arms folded.

[0271]FIG. 12E is a top view of the lifting layer with the armsextended.

[0272]FIG. 12F is a side elevation of tilting arms.

[0273]FIG. 12G is a side elevation of a tilting clamp assembly on afixture.

[0274]FIG. 12H is an end view of a tilting clamp assembly on a fixture.

[0275]FIG. 12I is a top view of a tilting clamp assembly on a fixture.

DETAILED DESCRIPTION

[0276] The application relates to various improvements to elements,structures, and components of structures used to support lighting andother loads, especially in entertainment and display applications.

[0277] In such applications, a wide variety of larger structures areoften assembled from the combination of a relatively limited number ofelongated structural shapes and fittings used to interconnect themand/or to attach them to other elements and to attach other elements andloads to them.

[0278]FIGS. 1A-1E illustrate five of the most commonly used elongatedstructural shapes.

[0279]FIG. 1A illustrates what is, by far, the most common shape inuse—tubing (including pipe) that is circular in cross section.

[0280] Such tubing is typically fabricated from one of two differentmaterials.

[0281] Commercially-available steel pipe is widely-employed, typicallyin the “1½” trade size and “Schedule 40” wall thickness. (The dimensionis that of its interior diameter, its “O.D.”, being approximately 1.9″).Such pipe is used as horizontal “battens” in fly systems; assembled into“grids”; and used as the basis of a variety of other structures, such as“booms” and “ladders”. Steel has high strength but also highself-weight.

[0282] With the need for portable structures, like trusses, havingmodest self-weight, tubing extruded from aluminum is in wide use,especially in the fabrication of such portable structures. Whileconsiderably lighter, aluminum tubing has lower strength and stiffness.Such tubing is typically employed in two diameters—a 2″ O.D. (which someclamps designed for 1½″ Schedule 40 steel pipe will not fit) and a 1.9″O.D.

[0283] Whether steel or aluminum, the circular cross section has bothadvantages and disadvantages, some of which will be discussed later. Onedisadvantage is the need to machine the end of a tube in a relativelycomplex shape where it intersects another tube in a weld.

[0284] As a consequence, some structures have been constructed fromtubing having a square cross section, as is illustrated in FIG. 1B. Thejoining of such members is comparatively simple, although the sharpcorners can be a hazard in handling, particularly after the aluminum isdamaged and burrs are raised in it.

[0285] As a consequence, a few fabricators have employed square tubingwith rounded corners, as illustrated in FIG. 1C.

[0286] Square tubing, whether rounded or not, has the added advantagethat through-holes for fasteners are easier to drill accurately than inround stock—but many of the clamps and other fittings designed to attachloads to round tubing cannot be used with it.

[0287] Another structural form used is the “unistrut” type trackcommercially-produced for electrical, plumbing, and HVAC work, as isillustrated in FIG. 1D. In contrast to the other shapes that require theuse of either a drilled pass hole and bolt or that require a clamp orother fitting to attach a load to the shape, “unistrut” permits theattachment of a load at any point along its length with only theinsertion of a compatible threaded insert, reducing the cost andeliminating the height loss and weight gain of clamp use.

[0288] More than one company has extruded a shape, illustrated in FIG.1E, that combines the “unistrut” track feature with a circular crosssection similar to 1.9″ or 2″ O.D. tubing, which has the added benefitof greater stiffness over a span; the ability to attach it to structuresand loads to it using clamps and other fittings designed for roundstock; and a chamber 106C that can accommodate wiring.

[0289] This application discloses a number of improvements to elongatedstructural shapes.

[0290] Such improvements include those having a purpose of increasingthe strength/stiffness of a shape of given material relative to priorart profiles, while maintaining an exterior profile that is compatiblewith the universe of clamps and fittings in present use.

[0291] Various Figures illustrate techniques by which these advantagesmay be gained, either alone or in combination with other features havingother benefits.

[0292] Refer now to FIG. 1F, a cross section of tubing 106 having acircular external profile 106E that can be identical to prior arttubing, but varies its wall thickness to increase its strength/stiffnessin one axis for only a modest increase in self-weight—in this example,by the use of an elliptical interior profile 106I.

[0293] In addition to varying wall thickness, the structural shape mayemploy other internal features to increase strength/stiffness in one ormore axes. FIGS. 1I-1U illustrate a number of such features, sometimesin the context of an embodiment that also illustrates other features,including unconventional external profiles.

[0294]FIG. 1I, for example, illustrates an internal web 109W that servesto substantially stiffen the shape for a modest increase in weight, andwithout impact on exterior profile. Similarly, FIG. 1J has a morecomplex internal structure 110W that increases stiffness in multipleaxes. Shapes having multiple internal closed voids are more complex toextrude, so other Figures illustrate shapes having features thatincrease stiffness (and provide other advantages) with simplifiedextrusion (although the method of fabrication—in one operation ormany—should not be understood as limited, except by the claims). FIG. 1Killustrates that the orientation of a stiffening web 111W, combined withan increase in wall thickness 111Y where the web orientation does notsignificantly contribute, can offer improvements in multiple axes.

[0295]FIGS. 1L-1Q illustrate embodiments in which variations in wallthickness increase stiffness and provide other advantages. FIG. 1L, asone example, provides four extruded ribs, 112R being one such rib, thatstiffen the tube. As illustrated in FIGS. 1N and 1P, these features (orothers) also permit the insertion of mating shapes, which are keyedagainst rotation by their relationship with the feature. In the exampleof FIG. 1N, an additional element, 124 is inserted in tube 114, beingkeyed against rotation by ribs like 114R, and retained in a fixedrelationship along the elongated axis of the tube 114 by a pin or otherelement inserted through holes drilled in the additional element (124B)and in the tube (114B).

[0296] It will also be seen that the additional element (in either FIG.1N or 1P) can be readily rotated 90 degrees with respect to theillustrated orientation and fixed there either by a second set ofsimilarly-rotated holes in the additional element or in the tube (e.g.114BB).

[0297]FIG. 1Q illustrates another embodiment in which wall thickness isincreased to increase stiffness and in which an additional element (here127) can be accommodated.

[0298]FIGS. 1R-1W illustrate the use of other internal features thatstiffen the shape without unduly complicating the extrusion and thataccommodate an additional element, here 130.

[0299] Illustrated embodiments key the additional element againstrotation. Designs can also permit rotation about the elongated axis ofthe shape without restriction and/or solely as determined by a fixingmethod, whether by design of the tube profile, the additional element,and/or the fixing method.

[0300] Another aspect of the invention is improvements to the exteriorprofile of the tube having additional advantages.

[0301] Refer now to FIG. 1G, which is an embodiment illustrated with aconventional internal profile but an improved exterior one.

[0302] The tube illustrated in FIG. 1G employs a generally octagonalexterior profile, whose rounded corners (e.g. 107C) fall within agenerally circular diameter, in this case, 1.9″. Thus, the tubeillustrated in FIG. 1G has the advantage of being useable with clampsand fittings designed for round tube. The flat surfaces it affords (e.g.107F) offer several advantages previously limited to square tubing,including the ability to prevent the tube from undesirably rotating in aclamp or bracket and/or a clamp or bracket supporting a load fromrotating around it. The facing flat surfaces it affords (e.g. 107F and107FF) allow rapid and precise drilling of pass holes required forfasteners. As illustrated in FIGS. 4P and 4Q, welded connections madebetween such tubing and cross-bracing in structures are simplified. Andthe improved shape can be more resistant to denting from excessive clampforce.

[0303]FIGS. 1M and 1Q illustrate other embodiments in which four sidesare curved and four are substantially flat. Other variations in thenumber of sides and in the number and sequence of sides that aresubstantially flat and substantially curved are possible, as areadditional features incorporated in the profile.

[0304]FIG. 1U, for example, includes a “unistrut” feature that providesthe capabilities of the prior art shapes of FIGS. 1D and 1E, as well asa recess 121S on both sides that could protect the head of a fastener; atape label (for example a bar code); or a “velcro” strip used to attachfabric masking. The same or a similar shape could accommodate guidewheels for travelling soft goods or other scenic elements or loads alongthe elongated axis of the tube.

[0305]FIG. 1W illustrates a tube having at least one recess 123R. Acomplementary protruding element on a clamp or fitting extending intorecess 123R prevents the tube from rotating in the clamp or fitting. Thedetail producing recess 123R also serves to stiffen the tube in multipleaxes, while it does not prevent the use of the tube with any prior artfitting or clamp usable with conventional round tube.

[0306] While structural shapes having an improved external profile canbe used with most clamps and brackets designed for round stock, theyhave certain advantages in maintaining the rotational relationshipbetween the shape and the clamp.

[0307] For example, certain clamps like the theatrical “C-clamp” and theEuropean “J” clamp have flat surfaces, which, when aligned with the flatsurfaces on the shape, will assure that the clamp (and its load) isaligned with that surface.

[0308] Clamps and fittings can also be designed to maintain theirrotational relationship with the improved structural shape.

[0309] As previously described, FIG. 1W illustrates a tube including atleast one recess 123R in its exterior profile that does not interferewith its usability with any prior art fitting or clamp, but permits itto be “keyed” to a clamp or fitting having a feature that extends intoit.

[0310]FIG. 2A is a side elevation of one half of a prior art “cheseboro”such as the ProBurger distributed by TMB Associates. This model isproduced from two machined extrusions: a base 201, and a cover 202,hinged together on one side (at 203) and held closed by a bolt 206pivoted at 204, bolt 206 carrying a washer and a wing-nut that bear downon the flange 205 formed in cover 202.

[0311] It is a problem that without the application of a high clampingforce in tightening the clamp (which may damage the wing-nut or bolt),tubing can undesirably rotate in the clamp under load.

[0312] The clamp of FIG. 2A illustrates in both its base 201 and cover202, one example of a profile at the clamp/tubing interface having bothflat areas (e.g. 201F) and curved areas (e.g. 201C). When a tube 107having the improved external profile is inserted in the clamp, severalof its substantially flat surfaces align with corresponding flatsurfaces on the base and cover, restricting the tube from rotation,despite only moderate clamping force.

[0313] A detailed view of the interface is found in FIG. 2C.

[0314]FIG. 2C is a composite view, the tubing 107 to the left of thedividing line, illustrating the interface between tubing having animproved profile and the clamp and the tubing 101 to the right of thedividing line illustrating the interface between a tube of conventionalcross section.

[0315] When a tube having a conventional circular profile is inserted inthe clamp, its external surfaces contact several areas on the clamp andits cover, including the curved areas.

[0316]FIG. 2B illustrates such a circular tube in a variant on the clampof FIG. 2A that illustrates an extruded hinge 203A requiring nomachining.

[0317] When two clamps are joined at their bases by a swivel to form a“cheseboro” they are free to rotate relative to one another about theswivel. Two keyways 209 and 210 are also illustrated, which, with aninterlocking shape, e.g. shape 212, and an additional slot milled in thebase at right angles to the keyways (indicated in this view by dashedline 211), allow the user to fix the rotational relationship between thetwo halves of the cheseboro quickly and easily in the field.

[0318] By insertion of the interlocking shape (e.g. shape 212) into oneof the keyways 209 or 210 in one clamp with the extending flange 212F ina keyway of the other clamp, the two clamps and their tubes are lockedin a parallel relationship—the choice of keyway used determining whetherthe two clamps open on the same or opposite sides. If the extendingflange is inserted in the milled slot in the other clamp, the two arelocked in a right-angle relationship. The interlocking shape can bereadily removed to change orientations or restore the “cheseboro” to“swivel” operation. FIG. 2B also illustrates a provision, by way ofexample, in the form of keyway 213, to insert a component thatrepresents a key that aligns with the recess 123R in shape 123illustrated in FIG. 1W, preventing the rotation of that shape relativeto the clamp.

[0319] Other variations in design are, of course, are possible. Forexample, a hole can be machined through base 201 with an additional,blind, hole at other locations. Inserting a length of rod in the firsthole that extends into the corresponding hole in the other clamp in acheseboro will lock the two in a rotational relationship, and multipleholes provide for different possible relationships The rod can bereadily moved to change the relationship or removed to restore thecheseboro to swivel operation. However, once a tube is in the clamp therod cannot escape. Another section of rod (for example) can be insertedin a blind hole to extend into the region occupied by the tubing,serving as the key engaged by a corresponding recess in a tube.

[0320] Other clamps and brackets are required for clamping round tubesto each other or to other objects. One example is the category offittings including Speed-Rail and Nu-Rail brands as produced by theHolleander Corporation. These are cast aluminum bodies drilled andtapped to accept set-screws used to fix the tube in the fitting.

[0321]FIG. 2D is a cross section illustrating one embodiment of animproved structural shape that can be used for many purposes. Theembodiment illustrated in FIG. 2D is illustrated as an extrusion 211having a larger chamber 211L that accepts tubing 200 and a smallerchamber 211S. Referring to FIG. 2F, it will be seen that a purpose ofchamber 211S is to accommodate a part 212 with an internal thread thataccepts a bolt or set-screw. When the bolt or set-screw is tightened,the threaded part 212, although it might have otherwise been free tomove along the elongated axis of the shape 211 in chamber 211S, will befixed in place relative to the shape, while the tubing 200 is alsofixed.

[0322] To accommodate a bolt or set-screw, passage is required throughthe shape to the tube, as is illustrated in FIG. 2E. This can beaccomplished by providing two continuous openings through the shape(211A and 211B)—which permit locating bolts or set-screws anywhere—or bydrilling or otherwise opening pass holes through the shape at locationsat which a bolt might be inserted—one technique that retains the bolt orset-screw and the threaded part at that location even when loosened.

[0323] Many different approaches to forming the threaded part 212 arepossible—including a standard hex or other nut; a plate having a tappedhole, or, as illustrated in FIG. 2I, the smaller chamber 211SS can beconfigured to employ “unistrut” track nuts as the threaded part byincorporating a suitable profile 211U.

[0324] The interior profile of the shape 211 can be designed toaccommodate different sizes and profiles of tube and, as illustrated inFIGS. 2G and 2H, employ a profile that provides for limiting to rotationof tubes having appropriate shapes (here illustrated as the use of aprofile similar to that employed in FIGS. 2A-2C)

[0325] The improved shape illustrated in these Figures has manyadvantages over prior art fittings. It removes the requirement that theentire shape/fitting be fabricated from a material and by a process thatwill permit tapped holes with threads of acceptable strength. In fact,the improved shape requires no tapping while it permits the use ofmaterials for the threaded portion that are far harder than those inprior art fittings. Unlike prior art fittings, such threads can also bereadily replaced when damaged or worn and changed to suit theapplication (for example, to vary the diameter of the bolt or set-screwand/or provide either metric or Imperial threads). A simple extrusionreplaces the need for cast fittings and can be used in many applicationswith little or no modification.

[0326] For example, a length of the illustrated shape can be used tocouple two tubes end-wise.

[0327]FIG. 2J is the first of a series of Figures that illustrate someof the methods by which a fitting like that illustrated can includeprovisions for attaching it to other objects, including other tubesand/or fittings.

[0328]FIG. 2J illustrates the addition of a flange 211W, which can beused for attachment to another object, including another section of thesame shape.

[0329]FIG. 2K is a cross section of a shape similar to that of the priorFigures having a flat surface 211B and two flanges (211F and 211FF) thatallow attaching the shape to other elements. For example, with flat 211Bin contact with a surface, flanges 211F and 211FF can be welded to thatsurface. FIG. 2L illustrates the shape with another structural shape 215welded it. FIG. 2M illustrates the use of another shape 216 havingfeatures (e.g. 216A) that interlock with structural shape 211, in thisexample, via flanges 211F and 211FF. The another structural shape 216may be fixed along the elongated axis of shape 211 by any one orcombination of a number of means, here illustrated as a threaded parttrack 216S similar to that used in shape 211.

[0330]FIG. 2N is a cross section of a shape similar to that of FIG. 2Kwhose flanges 211G and 211GG have been elongated relative to the priorFigure to accommodate pass holes (e.g. 211H) for bolts or otherfasteners. FIG. 2O is a side elevation of a length of shape 211 forminga fitting 211A on tube 200A and FIG. 2P is a top view of the samearrangement showing the flanges 211G and 211GG, the pass holes in them(e.g. 211H) and the set-screws (e.g. 213S) and threaded parts installed.Such a fitting 211A can be bolted or riveted to an object or structure.FIG. 2P is a side elevation illustrating that two such fittings 211A and211B can be bolted together (e.g., bolt and nut 214) via their passholes (e.g. 211H) to form a right-angle fitting joining two tubes 200Aand 200B at right angles. The pattern of pass holes like 211H in flanges211G and 211GG being square, the two fittings can just as readily bebolted together to hold the two tubes in parallel relationship.Additional pass holes and/or other arrangements (including, for example,brackets) will permit other angles and spacial relationships between twoor more tubes or a tube and a surface can be accommodated from a minimumnumber of modular parts.

[0331] Shapes used for fittings can be designed with details that permitmounting and/or interlocking that are milled or ripped off the basicshape when not required and can be permanently welded, bonded, orotherwise attached to form fittings.

[0332] Another aspect of the invention resides in improved structuralshapes that permit the ready attachment of loads as well as and theirown attachment to structures—both at any point along their length.

[0333] The prior art shapes commonly used for the purpose, the“unistrut” of FIG. 1D and the related shape of FIG. 1E have severaldisadvantages, most notably the difficulty of reliably inserting andengaging a track nut in the track and the ease with which the mostcommon nut types can be inadvertently disengaged from the track,releasing the load, which typically occurs when loosening or tighteningthe bolt attaching the load to the track nut, or when attempting toslide the track nut and load to another location.

[0334] Beginning at FIG. 3A are illustrated improved structural shapesthat provide all of the advantages of prior art “unistrut”track withadditional advantages and fewer disadvantages.

[0335]FIG. 3A illustrates one embodiment of a structural shape 301,shown here in paired use. Its profile includes two vertical surfaces301A and 301C that are offset to define a shoulder 301B. When used in afacing pair the result is an upper area 301D that is wider than a lowerarea 301E, and that together form a passage from one side of the pairedshapes to the other. That passage forms an elongated slot, as seen inthe top view of FIG. 3B.

[0336]FIG. 3C illustrates one use. Vertical surface 301A is located toproduce, in this embodiment, a space between such surfaces of a pairedset of such shapes a distance slightly greater than the width of thehead of a ½″ hex nut or bolt 310H across its flats. Vertical surface301C is located to produce a distance slightly greater than the shank310S and the thread 310T of such a bolt. The exterior profile of theshape 301 can be of any design, here illustrated as having an improvedprofile as illustrated in earlier Figures.

[0337] As illustrated in FIG. 3C in section and in FIG. 3D in top view,a ½″ bolt of suitable length is dropped into the passage formed betweenthe pair of shapes, coming to rest with the head 310H resting onshoulder surface 301B and between facing vertical surfaces 301A,substantially within the upper area 301D. The shank 310S and threadedportion 310T of the bolt extend between the facing vertical surfaces301C of the pair, through the lower area 301E, extending beyond thepaired shapes on the side opposite the bolt head 310H. A load, in thisexample the yoke 312 of a lighting fixture, is attached with the bolt bypassing the bolt through a hole in the yoke. Flat washers (e.g. 313) maybe provided.

[0338] It will be seen from FIGS. 3C and 3D that the load is positivelyattached to the paired shapes. If nut 311 is fully tightened, then thestack of yoke and washers will be pulled tight against the adjacent(lowest) portion of the paired shapes, while the underside of the bolthead 310H will be pulled tight against the shoulder surface 301B,preventing the rotation of both the yoke 312 around the axis of the boltand movement of the bolt along the slot formed by the paired shapes. Onthe other hand, partial loosening of nut 311 (as illustrated in FIG. 3O)permits the rotation of the yoke 312 around the axis of the bolt, andthe movement of the bolt and its attached load along the elongated axisof the paired shapes—without the possibility that the load might becomeinadvertently detached. Because the paired shapes offer verticalsurfaces 301A spaced only slightly away from the flats of the bolt head310H, the bolt will essentially not rotate about its axis so long as thebolt head is in the upper area 301D, simplifying the adjustment of nut311 (for example, requiring only one tool when compared withthru—bolting the prior art shapes of FIGS. 1A-1C). Substantially all ofthe bolt head is also recessed within the exterior profile of the pairedshapes (although in other embodiments—or with the simple expedient ofthe use of a flat washer under the bolt head—the bolt head may be abovethe overall profile and/or free to rotate.)

[0339]FIGS. 3E and 3F illustrate a use with the bolt inverted so thatthe threaded portion 310T extends above the profile and it is the nut311 that falls within the upper area 301D.

[0340]FIGS. 3G and 3H illustrate a use where the ability to rotate abolt whose head is recessed substantially within the overall profile isrequired (for example, when engaging a blind threaded insert in theload). In this example a “cap screw” having a cylindrical head 315H thatwill rotate continuously within the upper area 301D is employed.

[0341]FIGS. 31 and 3J illustrate a fastener that, like the prior art“unistrut track nut” permits insertion in the structural form from theload-side, including while attached to the load. Fastener 319 (which maybe formed integral or assembled from several components includingthreaded rod or a threaded fastener) has a head 319H, that isrectangular in plan, having one side 319L, that is slightly narrowerthan the width of the upper area 301D (which is to say, the distancebetween the surfaces 301A of a pair of shapes), and the other side,slightly narrower that the width of lower area 301E (which is to say,slightly less than the distance between the surfaces 301C of a pair ofshapes). The result is that the head 319H may be inserted through 301Efrom the load side until the lower surface of head 319H (the one thatwill rest on surface 301B of the paired shapes) is above upper area301D. Once rotated 90 degrees and lowered towards the paired shapes,head 319H will come to rest in upper area 301D, with head 319H retainedand prevented from rotation in the same manner as head 310H in FIG.3C—but cannot inadvertently fall thru area 301E when loosened foradjustment.

[0342]FIGS. 3K and 3L illustrate the use of a spacer 316 thatsubstantially fills the upper and lower areas. Extruded, milled, ormolded from the same or a different material it has several possibleuses. Inserted in the slot formed by the pair shapes where a compressionclamp (e.g., a “cheseboro”) will apply considerable force, it preventsthe “pinching” of the two shapes together. Attached to the paired shapeby bonding, welding, or mechanical fastener(s) (the last indicated bycenter line 317), it can be used to maintain a fixed relationshipbetween the paired shapes. Attached to the paired shapes, the spacerform may also be attached to another object or a structure, for example,by a fastener inserted through it (indicated by center line 318),attaching the paired shape to that object or structure.

[0343]FIGS. 3M and 3N illustrate a shape 331 having other features,notably a symmetrical design and a flange and recess in the shoulderarea that is engaged by the flanges (e.g. 335F) of a plate 335. Asillustrated in FIG. 3O in cross section and in FIG. 3P in top view,plate 335 has a pass hole 335H for the bolt. Downward pressure on thebolt 310 locks the flanges (e.g. 335F) of plate 335 into thecorresponding detail on the paired shapes, preventing them from splayingoutward even if excessive force is applied through the bolt.

[0344] FIGS. 3Q and 3QQ illustrate a spacer 338 adapted for shape 331,having the same applications as that illustrated in FIGS. 3K and 3L inconnection with shape 301.

[0345]FIGS. 3R and 3S illustrate a shape 341 using plates like 335 bothabove and below. These plates 345 and 346 include ramped flanges thatwedge into corresponding grooves formed in shape 341 by an “ear” 341F.Referring to FIG. 3S, a cross section through an assembly, it will beseen that clamping force on the bolt 310 causes the upper and lowerplates 345 and 346 to grip the “ears” tightly, transferring the load tothe paired shapes.

[0346]FIG. 3U is illustrates an external profile including an opening341G that interlocks (in FIG. 3Y) with corresponding shapes on amounting bracket 349 that does not extend below the profile of thepaired shapes. FIG. 3U is an interlocking internal spacer 342 withsimilar uses to that of FIG. 3K.

[0347]FIGS. 3V-3Y illustrate some methods of mounting the paired shapesillustrated in the prior Figures.

[0348]FIGS. 3V and 3W illustrate a bracket 321 used to attach pair ofshapes 301 to a surface represented by 320, while maintaining therelationship between them (the added clearance beyond the diameter ofbolt 322 required being produced, in this example, by sleeve 323 slippedover it).

[0349]FIG. 3X is generally equivalent to FIG. 3V, adapted for the shapeillustrated in FIG. 3M, FIG. 3XX being a view of bracket 339 isisolation.

[0350]FIG. 3Y illustrates a bracket 349 mounting the shapes illustratedfirst in FIG. 3T, which bracket could be used alone or in combinationwith spacer 342 of FIG. 3U, and with fasteners as required.

[0351] Another aspect of the invention relates to improved designs fortrusses and similar structures.

[0352] Long employed in various permanent applications, such as bridgesand roofs, over the last thirty years an industry has arisen around thedesign, manufacture, and provision of relatively lightweight trussesfabricated of aluminum, and intended for use in creating structures,often temporary, for the support of lighting equipment and scenicelements for live performances, special events, and displays (amongother applications).

[0353] Beginning in the early 1970s, companies supplying lighting andother equipment to such applications began designing and buildingtrusses for their own use. Because of the competitive advantages to begained with a truss of improved design and the relative ease with whichnew designs could be fabricated, a large number and wide variety ofdifferent designs have been produced over the years.

[0354] By the 1980s, increasing demand for such trusses led to the riseof specialist companies designing and manufacturing them for sale.Examples of firms designing and producing such trusses include: JamesThomas Engineering, Tomcat Systems, Total Fabrication, and SlickSystems.

[0355] Thirty years of intense competition has produced a wide varietyof truss designs.

[0356] Truss designs can differ in a number of parameters includingoverall form (flat, triangular, rectangular); dimensions; whether theyare intended to internally accommodate lighting or scenic equipment;whether they incorporate provisions to displace an internallyaccommodated load between an enclosed shipping and a more exposed useposition and/or incorporate hinged faces to perform the same functionand/or to reduce their volume for shipping; in the diameter and profileof structural shapes used for their main chords and/or forcross-bracing; in section length; in the method(s) by which multiplesections can be interconnected to form longer spans; and in whether theyincorporate casters—among others.

[0357] In a typical range of applications, and frequently within thesame application, there is a need for more than one truss design. Evenif the same overall genus of truss is employed (for example, simplerectangular trusses with no provision to enclose equipment or changeprofile) there is frequently a requirement for more than one trussdesign.

[0358] For example, there may be a need for a truss of sufficient widthto accommodate either one or two parallel rows of lighting fixtures orscenic elements and of sufficient height to allow reasonable spansbetween supporting points. Perhaps the most frequently-used truss designin such applications is the known “20.5″” design, as produced by severalmanufacturers, an end-wise view of which is presented as FIG. 4B.“20.5″” refers to the overall dimension across the cross section ininches.

[0359] Such trusses include four, parallel, main chords 401B, 402B,403B, and 404B that extend along the elongated axis of the truss anddefine its square cross section.

[0360] Typically, at the ends, and by perpendicular and/or diagonalcross-bracing at regular, intermediate points, the main chords areconnected by lengths of the same and/or another structural shape. In thecase of the end view of FIG. 4B, 405B, 406B, 407B, and 408B are thelengths of tubing connecting the main chords in a plane parallel to theillustrated face of the end of the truss section 400B.

[0361] Several methods have been employed to join multiple sections oftruss end-wise to form a longer span. A common method is to providebolt-plates parallel to the section end with pass holes, such that boltsmay be employed to join the section. In the case of the typical “20.5″”truss, sections of right-angle aluminum extrusion are often trimmed toform corner plates 411B, 412B, 413B, and 414B that are welded to theother members and afford pass holes 421B, 422B, 423B, and 424B for boltsused to join sections. Other truss designs or optional enhancements tothe same truss design allow the use of other or additional joiningmethods, such as “spigots” or fittings—such as clevis fittings.

[0362] In other applications, and frequently within the same application(such as a show, presentation, or display) that employs a truss like the“20.5″” design, there will be a need for a truss of less width—forexample, where only a single row of lighting fixtures or a single scenicelement need be supported, and the width of a larger truss would beexcessive, obstructed by or obstructing other nearby elements.Frequently, in such situations, a “12×12” truss, as illustrated in FIG.4A, is employed—the designation referring to the overall dimensions ofthe truss in cross section in inches. As will be seen from the end-wiseview in FIG. 4A, the “12×12” truss employs the same four main chords,similar interconnecting members, and similar end plates (e.g. 413A)affording pass holes 421A, 422A, 423A, and 424A for bolts used toconnect multiple sections (or a section to a base plate, corner cube, orother object).

[0363] While desirably narrower in width (12″ versus the 20.5″), thesimilarly-reduced height of “12×12” results in a reduced load-carryingability reducing allowable spans between supports, relative to “20.5″”.This undesirably complicates its use.

[0364] In applications (like events in hotel ballrooms) with limitedceiling heights, the height requirements of a truss like “20.5″” may bedeemed to unacceptably reduce the maximum height (or “trim”) of loadssupported from it, and specialized “ballroom truss” may be required,which has a similar width, but reduced height.

[0365] The requirement for multiple truss types complicates inventory,handling, transport, and installation.

[0366] Refer now to FIG. 4C, a simplified end-wise view of an improvedrectangular truss 400C. Like the prior art trusses of the prior Figures,it employs four main chords 401C, 402C, 403C and 404C. In thisembodiment, it employs an end-plate detail that is illustrated with passholes 421C-428C for connection to another section or object.

[0367] The embodiment illustrated has overall dimensions of nominally20.5″×10.25″—or one-half the cross section of “20.5″” truss.

[0368] It will be seen that, in the orientation illustrated in FIG. 4C,the improved truss will have an overall width of approximately 10.25″and a height of 20.5″. In most applications in which “12×12” truss iscurrently employed, the improved truss 400C will offer an even thinnerprofile while, by virtue of its greater height, supporting greater loadsover longer spans—simplifying its support or suspension.

[0369] In FIG. 4D, the improved truss has been rotated 90 degrees,illustrating that the same truss can be used in “low-profile” or“ballroom” applications—affording two chords at a spacing identical to“20.5″”.

[0370] Referring now to FIG. 4E, two such improved trusses (400C and400CC) are illustrated side-by-side, preferably mechanically connectedwith each other (one possible method to be illustrated in laterFigures). The result is a “compound truss” with the same profile as20.5″ and placing four chords (401C, 402CC, 403CC, and 404C) in the samelocation (as well as four additional chords along the centerline, e.g.403C and 404CC). The additional structure of the pair of improvedtrusses, relative to prior art “20.5″” results in greater load-bearingcapacity (and/or alternatively, allows a corresponding reduction instructure to produce parity).

[0371] Referring to the pattern of pass holes, it will be seen thatholes 421C, 422CC, 423CC, and 424C can be made to correspond with holes421B, 422B, 423B, and 424B of prior art “20.5″” truss, allowing directinterconnection of the two truss types. Further, the additional passholes of the improved truss can be used to increase the load-bearingcapacity of a span of such trusses.

[0372]FIG. 4F illustrates a coupled pair of improved trusses 400A and400B rotated 90 degrees relative to the prior Figure, with the benefitof reducing the amount of cross-bracing in the vertical axis, improvingaccess from above to loads hung below the compound truss.

[0373] In either case, it will also be seen that, in a continuous span,a transition can be made from a coupled pair to a single section, theprovision of the additional pass holes 425C-428C permitting suchtransitions regardless of the relative orientations of the sections atthe transition. (It will be understood that only a fifth and sixth suchpass hole (e.g. 425C and 426C) are necessary to provide this capability,the seventh and eighth holes (e.g. 427C and 428C) simplifying alignment.

[0374]FIG. 4G illustrates that “compound” trusses can be assembled withmore than two sections for increased dimension and/or strength.

[0375] It will be apparent that provisions can be made to couple twosuch trusses along their narrower dimension to produce a taller“compound truss” having substantially greater strength and allowablespan due to its increased height—as well as coupling trusses in parallelin both axes.

[0376] While the illustrated embodiment is based upon the dimensions of“20.5″” truss, it will be apparent that other dimensions can beemployed.

[0377] For example, in the illustrated embodiment, an additional trussdesign measuring approximately 10.25″×10.25″ can be employed—and willintermate with the 10.25″×20.5″ in a manner analogous to therelationship between a single section of the 10.25″×20.5″ and a compoundpair.

[0378] Another family of trusses could be based around 12″×12″, using a12″×24″ section that can be coupled to form a 24″×24″.

[0379]FIGS. 4H-4K are elevations illustrating possible designs for facesof a truss section—those faces parallel with its elongated axis. Whilegenerally equivalent to at least some sides of some prior art trusses,the Figures illustrate two features.

[0380] Members are illustrated as 431-434 (details of which will be seenin later Figures) that provide aligning pass holes (e.g. 431A and 431B)that permit coupling any two such sections in parallel, as illustratedin FIGS. 4E-4G.

[0381] Further, as a result of handling, a section of truss can berotated both about its long axis and end-for-end into eight possiblerelative orientations for a square truss and four for a rectangular onethat will appear to align. Trusses incorporate cross-bracing, sometimessimilar on all sides, sometimes diagonal on at least the two sidesnominally vertical and perpendicular (or “ladder-style”) on the others.Wherever such diagonal bracing is used, structural strength requiresthat the braces on adjacent truss sections form a continuous pattern,which may not be the case if two sections are in different relativeorientations. Without extra care in handling, such differentorientations can result.

[0382] In the illustrated example, a similar cross-bracing method isused on two opposing sides but, when such braces are asymmetrical (asare diagonal braces), are reversed relative to each other. The result,so long as the sections are oriented with the same end-for-endorientation, is, whether square or rectangular, that any relativerotation of two sections about their long axis will still result in astructurally correct result (and end-for-end transpositions are lesslikely in handling). As a further benefit, if the section joining methodhas a sexuality (for example, clevis fittings or a threaded insert) allcouplings on one end can be made the same sex (or, in the case ofrectangular trusses, sex can be reversed between opposite corners) withthe assurance that any relative orientation will work. (In the case ofthe provisions for joining sections in parallel, sexes can be alternatedto produce “universal connectivity”.)

[0383]FIGS. 4L-4O detail improved approaches to truss section end design

[0384]FIG. 4L is a detail side view of one end of truss as is alsoillustrated in FIGS. 4I and 4K that shows the cutting planes andperspectives employed by the following Figures.

[0385]FIG. 4M is a cross section through the end of one embodiment ofthe prior Figures on a cutting plane illustrated in FIG. 4L, lookingtowards the short side of either FIG. 4H or 4J.

[0386]FIG. 4N is a cross section through the end of one embodiment ofthe prior Figures on a cutting plane illustrated in FIG. 4L, lookingtowards the truss end.

[0387]FIG. 4O is an elevation of one end of the embodiment of the priorFigures, showing additional detail.

[0388] Referring now to these Figures, several features will be seen.

[0389] In the illustrated embodiment, unlike those prior art trussesillustrated in FIGS. 4A and 4B, tubing is not used to connect the mainchords at the section end. Instead, two extrusions 431 and 433 are eachattached to two chords, for example, 401C and 404C in the case of 431.The illustrated extrusion is essentially a right angle, one side ofwhich 431F, parallels the side of the truss section, and providespoints, here pass holes 431A and 431B, used to couple two such sectionsin parallel. A reinforcing flange 431E is illustrated. In theillustrated embodiment, side 431F of the extrusion is milled away at itsupper and lower ends to permit contact between it and the tubing formingthe main chords along the latter's elongated axis as well as a buttcontact to the other face 431G of the same extrusion 431. Welding and/ormechanical fasteners are used to attach them.

[0390] Two such extrusions 431 and 433, each attached to two main chords(and their inter-connecting cross-braces), are themselves brought intocontact with a plate 440 that forms the truss end visible in FIG. 4O.The extrusions 431 and 433 are attached to the end plate 440 by weldingand/or other means, for example by welds along their interface at 431Yand 431Z. Aligned pass holes 421-429 for the bolts used to join sectionsare provided in both the extrusion 431 or 433 and the end plate 440,such that the joining bolts extend through both and that the joining ofsections (or a section with a corner, base, or other object) actuallyreinforces the bond between the extrusions and plate and distributes theload through both. Other designs are certainly possible, the illustratedembodiment having the benefits of requiring one extrusion of relativelymodest size and a piece of plate. Different alloys or materials can beused for the two parts (subject to appropriate joining methods) and itwill be apparent that same extrusion can be used in different lengthsand with plates of different sizes to assemble many different trussdesigns.

[0391] In truss design, the location of a joining connection offsetsignificantly within the vertical centers of the main chords may impactthe load-bearing capacity at the joint between sections. FIG. 2N andFIG. 2O illustrate pass holes (e.g. 429A and 429B and 430A and 430B)that are substantially aligned with the vertical centers of the mainchords.

[0392]FIG. 4O also illustrates openings (e.g. 440B) in the plate alignedwith the main chords whose purpose will be described in connection withlater Figures.

[0393]FIGS. 4R-4Z illustrate other improved methods of trussconstruction.

[0394] Trusses (whether flat—also known as “ladder beam”) or dimensionalwith a polygon cross section, typically rectangular or triangular)require cross-bracing between the main chords. Such cross-bracingrequires a structural connection where the shape used for thecross-brace and that used for the main chord meet, which may be at rightor other angles.

[0395]FIGS. 4P-4Q illustrate an intersection between a cross-brace and amain chord 401. By the use of a shape for the main chord having thegenerally octagonal shape disclosed earlier, the intersection betweenthe cross-brace 409 (here a rounded rectangle as seen in cross sectionin FIG. 4R) is simplified as seen at interface 409C and 409D—requiringrelative simple trimming of the cross-brace end and straight welds.

[0396]FIGS. 4S-4V illustrate another approach to the cross-brace issue.Here, the shape for the main chord 122, incorporates an opening 122Rinto which the end of the shape used for the cross-brace (here a roundedrectangle, 409C seen in cross section in FIG. 4V) can be inserted. Thetwo shapes can be fixed relative to each other by mechanical fastening,bonding, and/or welding—for example, straight welds along the interfaceat 409D. It will be seen that this approach requires only a straight cutacross the end 409E of the cross brace 409C with relatively lowtolerances, and that any angle of intersection can be accommodated by achange in the angle of cut. This approach offers particular economy inthe construction of “flat truss”, which requires cross-bracing in onlyone plane.

[0397]FIGS. 4W-4Z illustrate one method by which a shape can beselectively reinforced along its length.

[0398] Such reinforcement may be desired to better distribute a loadapplied to the shape locally (for example, at a load-bearing connection)and/or as reinforcement for wear (for example, at a point of repeatedinsertion of a locking pin).

[0399] In this embodiment, the structural shape first illustrated inFIG. 1V is shown. In addition to the opening 122P, the shape includesvoids (e.g. 122V) formed between its flatted external surface at 122Band internal member 122A. A reinforcing shape 124 is formed (forexample, milled) out of the same or different material—in this case,steel. A length of reinforcement 124 is inserted in the void 122V inshape 122 at the required location. Many methods for fixing it in placeare possible—in FIG. 4W roll pins 122S and 122T are illustrated asinserted through aligned pass holes in both the reinforcement 124 andthe shape 122. In the example, the reinforcement is applied at thelocation of pass holes 122E and 122F for locking pins as might be usedto attach sections together. The reinforcing shape 124 on the oppositeside of shape 122 is shown only partially inserted in its void so thatthe pass holes in it for the locking pins can be seen. FIG. 4Y is adetailed view of a section at the location of pass hole 122Eillustrating the pass holes in both members 122A and 122B of shape 122and in reinforcement 124. Also illustrated is the radiusing of the passhole on the external side to simplify insertion of the locking pin.

[0400] Many methods of reinforcing the shape are possible and should notbe understood as limited. FIG. 4Z illustrates a reinforcement 125 thatis fabricated of a laminated stack of relatively thin stampings. Asuitable compound can also be injected into the void.

[0401] Similarly, reinforcing techniques are not limited to shape 124.It will be seen that many of the improved shapes illustrated in FIGS.1F-1W (and others not illustrated) can be readily reinforced.

[0402]FIGS. 5A-5Z illustrate improved methods of joining truss sectionswith each other and with other objects and structures.

[0403] For reasons of practicality in shipping and handling and forversatility, most truss sections are fabricated in sections of 10 feetin length or less and typically in a selection of lengths. Sections areprovided with at least one mechanical method for coupling multiplesections end-wise to form a longer span of the required length.

[0404] Many joining methods have been employed over the last threedecades, the most common of which remains a bolted connection.

[0405] As illustrated earlier in FIGS. 4A-4C and others, sections areprovided with a structural plate or plates or other forms providing passholes for bolts that are inserted with their long axes parallel with thelong axis of the truss. As illustrated in FIG. 5A (which is a sectionalview equivalent to FIG. 4M) two adjoining truss sections have parallelend plates (here 440 and 440D). A bolt 510 is inserted through the passhole 421D in the end plate 440D of one truss section and through thepass hole 422 in the end plate 440 of the other truss section and a nut511 threaded to it. When the bolt 510 is tightened, the two end plates440 and 440D and their trusses are drawn together.

[0406] The illustrated bolting method has advantages and disadvantages.The connection is relatively cheap and is genderless. The nuts, bolts,and washers are, however, loose parts that require handling andre-assembly each time the sections are joined or separated. Two wrenchesare required, one on the bolt head, one on the nut, to prevent the boltfrom simply free-spinning. The truss is typically at floor level,requiring the work to be done on hands and knees, and a givenapplication can require dealing with a hundred or more bolts—at asignificant cost in time and labor.

[0407]FIG. 2B illustrates one improvement: the captivation of the nut.Here, nut 511A is illustrated as retained by, in this case, a formedsheet metal bracket 515 that is attached to either shape 432 and/or endplate 440. Only bolt 510 and an associated washer 513 are loose parts.Only one wrench is required as the dimensions of the channel for thebolts formed in bracket 515 can be limited to prevent rotation of thenut. The dimensions of the channel (and the method of retaining the boltalong the length of the channel) can allow sufficient “play” to make thenut self-align with the hole, and, of course, a washer can also beaccommodated, if desired.

[0408] In this example, the bolted connection between truss sectionsend-wise places a nut on one section end and a bolt on the other, while“compound trusses” are created by similar connections between sectionsside-to-side. Thus, bracket 515 retains nuts for both end (515A) andside (515B) connections, and bracket 516 for end connections only.

[0409] In addition to formed sheet metal, brackets can be fabricatedfrom an extrusion, a detail on which can interlock with a compatibledetail on the truss structure, reducing or eliminating the requirementfor mechanical fasteners to attach the bracket.

[0410]FIG. 5C is an oblique view of the end of the truss section withshapes 431 and 432 and end plate 440, illustrating how an elongatedbracket can accommodate multiple fasteners. Indeed, a single bracket canretain all of the hardware required on one side of the truss, in theexample of FIG. 4O, as many as six sets.

[0411] It will also be apparent in connection with any previous or laterembodiment, that the bolts can be made captive as well.

[0412]FIG. 5D illustrates the addition of a detail that retains thewasher associated with the bolt. Bracket 518 is illustrated asaccommodating a bolt on its end-side 518A and a washer on its side-side518B. Similarly, bracket 519 inverts the relationship (and, in asymmetrical design, might be the same bracket used for bracket 518,inverted). Bracket 520 is designed to retain washers on both sides 520Aand 520B.

[0413] It will be apparent that a “washer” bushing or sleeve can also beused on the bolt side that is the same depth as the nut, resulting in auniform bracket design.

[0414]FIG. 5E illustrates one embodiment in which the nut or otherthreaded receptacle is retained by a detail made integral with the trussitself. Corner member 432 is illustrated with two integral rails 432Eand 432G that define a track that retains a nut or threaded insert 521.

[0415]FIGS. 5F-5H illustrate details of one possible insert design.FIGS. 5F and 5G represent two elevations and FIG. 5H a top view ofthreaded insert 521, which includes a threaded hole 521T and a smallerhole 521S.

[0416]FIGS. 5I-5K illustrate its installation. FIG. 5I is a reverseelevation of the face of shape 432 interior to the truss section,showing the pass hole 432H for the bolt and an adjacent hole 432S. FIG.5J is the same view and FIG. 5K a section, both with threaded insert 521installed, the threaded hole 521T in it in substantial alignment withpass hole 432H (corresponding, for example, to 422 in the earlierFigures) in shape 432 and in end plate 440. (In FIG. 5K, rails 432E and432G are not shown for clarity).

[0417] Threaded insert 521 is retained in position, in this example, bythe expedient of a part 522 that protrudes into hole 432I in shape 432.One such part may be a fastener mating with threads in either the insert521 or the hole 432I in shape 432 (or in end plate 440 beyond it).Alternatively, the simple expedient of a plastic plug or wooden dowelpress-fit into one of the holes will serve. It will be apparent that thedifference in diameter and/or shape between the part 522 and the hole onone part can be used to determine the distance by which the insert will“float” relative to the hole.

[0418] Another method of retention is a plug or fastener insertedthrough the shape 432, its rails, or a bracket above and below the nutor threaded insert, which prevents or limits movement of the insertthrough the track defined by the rails.

[0419]FIGS. 5L and 5M illustrate another retention method—a spacer shapeis inserted in the track formed by the rails 432E and 432G. This methodhas advantages when multiple nuts or inserts are used in the same track.Several sections of spacer shape (e.g. 523 and 524) with nuts or insertsinterspersed can, by the choice of appropriate lengths, determine thespacing between multiple nuts or inserts, and require only a limitednumber of connections to the truss, either by fixing inserts and/orspacers in place (in the example illustrated in FIGS. 5L and 5M, bothmethods are illustrated in the form of part 522 and threaded fastener525).

[0420] In trusses using a formed track, inserts and spacers can beinserted and changed in a fabricated truss where at least one open endof the rails remains exposed, as in the embodiment illustrated in FIGS.4N and 4O. In other designs in which the ends are closed by the trussdesign, the protruding portion of the rails can be machined away for alength sufficient to insert or remove an insert.

[0421]FIG. 5N illustrates the use of the same rail detail on both sidesof the truss-truss connection. A non-threaded insert 526 with a passhole is inserted in the track on the bolt-side of the connection. As isalso illustrated in FIGS. 5F-5H, the shape employed for insert 526 has aflat surface 526F proud of the surface 434F of rails 434E and 434G, suchthat the clamping load of bolt 510 is transferred to the main body ofshape 434D by the insert rather than by the head of bolt 510 bearing onthe surfaces of rail 434E and 434G.

[0422]FIG. 5N also illustrates both threaded (521A) and non-threaded(526A) inserts that can be inserted and removed.

[0423] There are circumstances in which the user may desire to change apass hole from threaded to un-threaded or vice versa.

[0424]FIGS. 5O-5S illustrate one method of achieving the benefits ofretained hardware with the ability to rapidly change between threadedand unthreaded holes.

[0425]FIGS. 5O-5Q are two elevations and a top view equivalent to FIGS.5F-5H. A profile similar to that of inserts 521 and 526 is used in agreater length and with both a threaded hole 527T and an unthreaded passhole 527H. FIG. 5R is an oblique detail equivalent to FIG. 5C showingsuch inserts in the tracks formed by the rails. FIG. 5S is a sectionshowing the adjoining ends of two trusses (the rails, again, suppressedfor clarity). The user can manually slide the insert 527 in the track toalign the desired hole in the insert with the pass hole in the trussend. Fasteners, pins, or dowels (or another method) are used as stops tolimit the movement of the insert in the track. As illustrated, whenresting on stop 529 insert 526 aligns threaded hole 526T with the holethrough shape 432 and end plate 440. Stop 528 limits the travel of theeinsert 527 such that the unthreaded pass hole 527H aligns with the samehole. A detent can be used to maintain the insert at one limit or theother. For example, a blind hole 327R in the insert can retain acompression spring 530 that bears against the adjoining face of shape432. Other methods of resisting inadvertent displacement of the insertcan be employed and the detent can engage details (example, holes like432I) to align the selected threaded or unthreaded hole in the insertwith the hole in the truss.

[0426]FIG. 5R is an oblique view. The track detail in shape 432illustrates a dual function insert 526. The track detail in shape 434illustrates an extended section of insert 526B that provides threadedand unthreaded holes for a plurality of bolted connections.

[0427] Many other approaches are possible and should not be understoodas limited, except by the claims.

[0428] In addition to bolted connections, other methods of joining trusssections are employed.

[0429] Another form of connection, a “spigot”, refers generally to afitting that protrudes beyond the nominal end of the truss structure andis provided in male and female versions. A male “spigot” on one trusssection is mated with a “female” spigot on another truss section, andthe two fixed together using a locking feature such as a pin. Typically,each truss section employs one such spigot at the end of each of itsmajor longitudinally-extending members or “chords”. The most common typeuses fork-like “clevis” connections. Such fittings are fabricatedseparately and attached to the chords of a truss section eitherpermanently (by pinning, welding, or hydraulically swaging the chordtubing around recesses on the fitting) or temporarily with pins.“Spigots” have the advantage of requiring less time to mate than boltedconnections; requiring few or no tools; and being easier to inspect (aswhether a bolted connection has been fully tightened is not readilyvisually apparent).

[0430] “Spigots” may be of one-piece construction, or may be fabricatedin two parts: a receiver that is permanently installed in the trusschord, and a fitting that may be inserted in or removed from thereceiver—or its orientation changed—to meet current requirements.

[0431] Over the years, various designs have been employed, both for thefittings themselves and for their method of attachment to their trusssection and to the mating fitting.

[0432] Any of the prior art spigot designs may be employed.

[0433]FIGS. 5T-5Y illustrate various approaches.

[0434]FIGS. 5T-5V illustrate the use of conventional male and femaleclevis fittings (551 and 552 respectively). Both fittings (cast,machined, or otherwise fabricated) have elongated tangs (551E and 552E)that are inserted into the truss chords and retained either temporarilyor permanently. In this example, tangs 551E and 552E extend into thetruss end and are provided with pass holes 551H and 552H that align withpass holes (e.g. 401H) in the truss chord 401, through which fasteners,whether temporary or permanent, are inserted.

[0435] Tangs 551E and 552E may be equivalent to the forms 124, 126, 127,or 130 of FIGS. 1N, 1P, 1Q, or 1T.

[0436]FIGS. 5W-5Y illustrate another approach.

[0437] In this embodiment, a tang 553 is retained in the truss chord 401by means of the pass holes 553H and 401H like those illustrated in theprior Figures and of pins 556 and 557. There may be a compatiblereceiver installed in the chord of the mating truss section (here 400D)or, as illustrated, for example, in FIGS. 1N, 1T, 4P, or 4T, the profileof the tube used for the chord itself may provide such a form, in whichthe other end of tang 553 is held by locking pins 558 and 559 throughpass holes 553G in tang 553.

[0438]FIG. 5W also illustrates an improvement in which the fitting (inthis case, tang 553) can be recessed into the chord of the truss itselfwhen its use is not desired. Compression spring 560 is inserted withinthe truss chord and retained by a fastener at 561 or other means. Torecess the fitting, the user pulls pins 556 and 557 and pushes thefitting tang 553 until the other set of pass holes 553G in tang 553align with pass holes 401H in the truss chord. Pins 456 and 457 arereinserted, locking the tang 553 in its recessed position. When use ofthe tang is desired, pins 556 and 557 are pulled and spring 560 servesthe function of urging the tang 553 outwards so that the user can graspit and pull holes 553H into alignment with holes 401H, where the pins556 and 557 are reinserted, locking the tang 553 in its extendedposition.

[0439] In addition to the need to join sections of truss end-wise tocreate longer spans, there is also a need to join them at right angleswhen forming larger structures. For this purpose “corner blocks” havelong been employed.

[0440] A “corner block” is typically a cube (if the truss is square incross section) fabricated of structural shapes that provides for thesame joining method as employed by the truss on each of between threeand six of the “corner block's” sides. An elevation of a “corner block”for “20.5″” truss, for example, will typically resemble an end view ofsuch truss, e.g. FIG. 4B.

[0441] Beginning at FIG. 6A are illustrated various possible embodimentsand details of a unit that serves the function of a “corner block” andmany more.

[0442]FIG. 6A is an elevation on one side of a unit 600 as adapted forone group of truss types. Prominent is a plate 601, in some respectsanalogous to plate 440 of prior Figures in that it provides a variety ofholes (e.g. 601H) for attachment.

[0443] As illustrated in FIG. 6A and other Figures, plate 601 includes anumber of holes 601H of three shapes.

[0444] Refer now to FIG. 6B, a detail of the hole pattern illustrated inFIG. 6A. For ease of description, holes are referenced by a columnletter (A-E) and by a row letter V-Z) and may be identified by atwo-letter designation that specifies their coordinate (for example, thehole 601H in the top right corner of the Figure is hole “EV”).

[0445] A number of holes and of hole shapes are provided to permit awide variety of connections between the plate 601 and various trusstypes.

[0446] Columns A and E and rows V and Z are on 13.75″ centers, spacingholes AV, AE, AZ, and EZ to correspond with holes 421B, 422B, 423B, and424B of standard “20.5” truss, as was illustrated in FIG. 4B. Thus plate601 will mate with known “20.5″” truss.

[0447] Columns B and C and rows W and Y are spaced on 6.75″ centers.Column C and row X employ elongated holes that include a 6.75″ centerrelative to both the A and E columns and the V and Z rows. Hole CX iselongated in both axes to produce the 6.75″ center to columns A and Eand rows V and Z. 6.75″ is the hole pattern employed by prior art“12×12” truss as was illustrated in FIG. 4A. Thus, a section of “12×12”truss can be mated with plate 601 in any one of nine possiblealignments—in all combinations of left, centered, and right verticallyand high, centered, and low horizontally.

[0448] The “20.5×10.25” truss earlier described will mate in fourpossible orientations.

[0449]FIG. 6C adds additional mounting holes. The four holes on the Fand G columns (holes FV, GV, FZ, and GZ) allow “20.5×10.25” truss to bemated while aligned on the vertical center of unit 600. The five holeson the “U” row allow the mating of known “12″×18″” truss in a verticalorientation and a left, centered, or right alignment.

[0450] It will be apparent that other and/or addition hole patterns canbe used.

[0451] It will be seen that a hole pattern like that illustrated willaccept a variety of truss types in a large number of orientations. Whileillustrated as a plate, it will be apparent that many methods ofproducing the same or another interface are possible using otherfabrication methods. The holes illustrated may be simple pass holessimilar in principle to those illustrated in FIG. 5A and/or can employother or additional features including threads or threaded inserts,other fastener types, and/or “spigots”.

[0452]FIG. 6D is a section through unit 600 showing one method ofconstruction. Four plates (e.g. 601) are provided on each of fourperpendicular faces, and are joined by sections of a structural shape602 at each of their four adjacent corners.

[0453]FIGS. 6E-6G are detailed views illustration some of the manypossible designs for shape 602.

[0454]FIG. 6E illustrates the same shape 602 as seen in FIG. 6D, anangle that provides two flanges for attachment to a plate 601 by, forexample, welding along their interfaces. Pass holes in shape 602 (herehole 602H) aligned with the holes (here hole 601H) in plate 601 areprovided as necessary. A detail is illustrated at the corner, here ashape 603A, which is fabricated, for example, from wood, rubber orplastic, and serves as a protective bumper, which may be bonded orfastened in place.

[0455] In FIG. 6F, a similar protective bumper 603B is shown as retainedby a interlocking tongue-and-groove connection with a correspondingdetail 602I on the corner shape 602B, which also includes rails (e.g.602F) that accept threaded or unthreaded inserts as earlier illustrated.

[0456] In FIG. 6G, a stiffening rib 602G is illustrated, as well as anextruded corner detail 602J.

[0457]FIGS. 6H and 6I illustrate another embodiment 600B of the unitwith additional features.

[0458]FIG. 6H is a side view that illustrates the addition of casters(e.g. 604) and a stacking locator detail 605.

[0459]FIG. 6J is another elevation of a side perpendicular to the sideseen in FIG. 6H that differs in two respects: it has an overall widththat is 24″ rather than 20.5″ and it includes a handle detail (e.g.606).

[0460] (It will be understood that units having the features andimprovements described and illustrated in the application—and otherequipment—can be produced in many possible embodiments, including sizesand proportions. While an embodiment having faces of different width isillustrated in many of the following Figures, all faces could be of thesame width.)

[0461]FIG. 6J is another elevation from the same perspective as theprior Figure showing the unit illustrated 600B in use. Two sections oftruss (400B and 400BB) are attached to unit 600B (and additional trussescould be attached to the side 601S visible and/or the side opposite. Theunit 600B is suspended by spansets, cable, or chain bridle 656 from aknown chain motor 650, suspending the trusses 400B and 400BB (and anyother connected structure).

[0462] While all sides of the unit can be of equal width, they may alsodiffer and FIG. 6K is a cross section of a corner shape 602K forming anangle with unequal legs that attach to the plates 601E and 601S of twosides of different width.

[0463] Prior sections have been through a horizontal plane. Beginning atFIG. 6L are a series of cross sections through a vertical plane,illustrating other aspects of possible designs.

[0464]FIG. 6L is such a cross section and provides a point of referencefor the various details seen in detail in the Figures following.

[0465]FIGS. 6M-6O illustrate several possible approaches to a shape forthe top edge of a unit having a substantially open top. All three shapes611A, 611B, and 611C incorporate a rounded top profile that isequivalent in location and shape to a main chord of “20.5″” truss—whichstiffens the top edge of plate 601, provides a comfortable grippingsurface, and has other advantages that will be illustrated in laterFigures. Any of these shapes can be provided with a detail for retaininginserts, such as rail 611F.

[0466]FIGS. 6P-6R illustrate several of many possible approaches to ashape for the bottom edge of a unit 601 that has details like thoseillustrated in the prior Figures. All three shapes 612A, 612B, and 612Care illustrated with a flange (612E, 612F, and 612F respectively) thatcan be used as a point of attachment to the unit 600 when it issuspended (as was illustrated in FIG. 6J)—as is illustrated by theattachment of a shackle 657 whose bolt is passed through a hole 612Hprovided in flange 612G. Other illustrated details include a flat lowersurface (e.g. 612I) for the attachment of casters, a bottom plate,and/or other items. FIG. 6R elongates this feature to provide anenlarged mounting surface 612J and also illustrates the use of a rail612K as part of an insert retention detail.

[0467]FIGS. 6S-6U illustrate how unit 600 can be readily stacked onanother such unit or section of truss.

[0468] Referring to FIGS. 6T and 6U, there is illustrated a bottom edgeshape 612 very similar to the shapes illustrated in FIGS. 6P-6R.

[0469] A bottom plate 607 and casters (e.g. 604) are attached to thebottom edge shape 612, with the casters so located that, as illustratedin FIG. 6T then a unit 600 is stacked atop a section of truss forhandling, transport, or storage that they do not interfere (top chord401BL of the section of truss below is shown). FIGS. 6T and 6U alsoillustrate an additional part, stacking interlock shape 605 (also seenin prior FIGS. 6H-6J and 6L). As is seen from FIG. 6T, the profile ofstacking interlock detail 605 conforms to the external profile of thetubing (here 401BL) used for the main chords of one truss type withwhich the unit 600 is designed to be used, such that it positively locksthe unit to which it is mounted in alignment with the truss sectionunder it. As will be seen by comparison of FIGS. 6S and 6T, the bottomedge of unit 600 is preferably located and stacking interlock detail 605designed so that a unit 600 stacked on a truss section will have thesame overall height as two stacked truss sections. As will be seen fromFIG. 6U, the detail used at the top of the unit, here shape 611, isdesigned with an external profile similar in location and shape to thetop chord of a truss so that two such unit can be readily stacked andthat the resulting stack will be of the same height as a stacked pair oftruss sections. This will have benefits including the ability to shipassembled spans of truss sections that include those with a unitattached.

[0470]FIG. 6I illustrates a unit whose plate 601 includes a handledetail 606 that can be produced by machining or otherwise forming asuitable hand-hold opening in the plate 601 and in any shape orstructure behind it, in this case corner shape 602. The user's comfortand lifting ability are improved by an additional shape 613. While, inFIG. 6I, the handle details replace two mounting holes per side, FIG. 6Willustrates one method by which such mounting holes may be restored.Adapter 614 includes a threaded hole 614T that serves the function. Aportion 614A of the adapter 614 that extends into the hand-hole alignsit. Faces 614B and 614C bear against shape 602, transferring the load onthe bolt into the structure. Such an adapter could be retained on ahinged connection or other captivating connection.

[0471] In addition to connecting with truss sections, the unit canconnect with tubing by any one or combination of several means.

[0472]FIGS. 7A-7L illustrate a unit having integral provisions forattaching tubing.

[0473]FIG. 7A is an elevation showing four recesses 715A-715D, each ofwhich can accept a tube. FIGS. 7B-7M illustrate some of the possiblemethods of integrating provisions to attach such tubing into the unitstructure.

[0474]FIG. 7B illustrates a shape 712B, here adapted for the lower edgeof the unit, that includes a cylindrical opening 712L that receives thetubing and includes a detail 712S like that illustrated beginning atFIG. 2C for accommodating a nut plate to fix the tube in position.

[0475]FIG. 7C illustrates a shape 722C that incorporates a flange 712Ffrom which the unit can be suspended, here via shackle 657.

[0476]FIG. 7D illustrates a similar shape 722D, which can be suspendedby a wire rope loop 656L wrapped around the tubular member 712P via ahole or slot 712O opened in the flange connecting the tubular and angledportions of the shape.

[0477]FIG. 7E illustrates another shape 712E also having an opening 712Lthat receives the tube and a recess 712SS that can accommodate one ormore fitting types. Fitting 722 is a shape that is accommodated withinrecess 712SS. Seen in an end elevation in FIG. 7H and in side elevationin FIG. 7G, fitting 722 includes threads that receive a bolt 723 orother threaded fastener. In a manner similar to the shape of FIG. 2I andother Figures, tightening bolt 723 against a tube inserted in opening712L will fix the fitting 722 and the tube in place. To prevent thefitting from moving in the recess 712SS when not tightened on a tubemany methods can be employed. Here a pass hole 712P through the shape712E is illustrated, and a corresponding pass hole 722P through thefitting 722. A fitting may be retained in a given position by insertionof, for example, a known locking pin through both pass holes. If thepass hole 722P in fitting 722 is oversized relative to the diameter ofthe pin (at least in a dimension perpendicular to the tube's centerline)the fitting will be free to “float” slightly as the fastener 723 istightened on the tube, assuring that the load is transmitting to thetubing across the interface between the fitting 722 and the shape 712Eand not via the pin.

[0478] It will be apparent that there are many other suitable designsfor a detent that will maintain fitting 722 in a selected position.

[0479] In the Figures, fitting 722 has been fabricated so that the headof fastener 723 is recessed within the profile of the shape 712E.

[0480]FIGS. 7I and 7J illustrate shape 712E with two other fittings.Fitting 724 and 725 are designed for use in suspending the unit 600 orother unit in which they are employed. Both fittings 724 and 725 haveelongated tabs in which a pass hole (724H and 725H) is provided forattachment (of shackle 657 in the case of fitting 725). Pass holes (e g.725P) is provided for maintaining the fitting in position.

[0481] In suspending a load it can be necessary to shift the point ofattachment to compensate for variations in the location of the load'strue center-of-gravity. FIG. 7M is an oblique view of shape 712E withfitting 725 inserted. A plurality of pass holes 712P are shown in shape712E, permitting the fitting 725 to be maintained in any one of a rangeof possible locations to move the point of attachment to thecenter-of-gravity.

[0482] There are many methods of providing for a range of attachmentpoints, which should not be understood as limited. In the case of shapes612A-612C of FIGS. 6P-6R or 712C or 712D of FIGS. 7C and 7C, the flangecan be provided with holes or slots in multiple locations. Anothermethod would be to provide teeth or a similar detail at the interfacebetween the fitting and shape 712E (whether integral to the fittingand/or shape or by means of an additional element). A spring might urgethe two interlocking details together when not under load. The usercould relocate the fitting by pressing the fitting into the shape,overcoming the spring and separating the interlocking details. Whenreleased at the new position, the spring would urge the interlockingdetails together. The interlocking details could not be separated whenthe fitting was suspending the load.

[0483] The prior Figures illustrate some of the possible methods bywhich a tube can be fixed to a unit or other structural element by ashape having other purposes. Various types of clamp or fitting can, ofcourse, be attached to the unit or shape, on a temporary or permanentbasis, to perform the one or multiple functions.

[0484] Beginning at FIG. 7N are illustrated methods of attaching tubesto the exterior of a unit or other structure.

[0485] Illustrated in FIG. 7N is end elevation and in FIG. 7O in sideelevation is an elongated bracket 730 provided with pass holes (e.g.730H) that align with the hole pattern on the unit 600B. The bracket 730is dimensioned so that it accommodates a tube (e.g. 200) and that whenbolts (e.g. 731B) are tightened down, that the tube is firmly clampedbetween the bracket 730 and the surface of plate 601, preventing eithermovement or rotation of the tube. FIGS. 7P and 7Q illustrate twoexamples of bracket 730 (here brackets 703A and 703B) in use to attachtwo tubes (here 200A and 200B) to a unit 600B.

[0486]FIGS. 7R through 7V illustrate other embodiments of fittings usedto fix tubes to a unit or structure.

[0487]FIG. 7R is a cross section through a structural shape 760 (whichmay or may not be formed by extrusion) that includes a large opening760O that can accommodate a tube 200 and, in this embodiment, a smalleropening that can accommodate a threaded insert 762 that accepts afastener 763, which is used to fix tube 200 in shape 760. Shape 760 alsoincludes an elongated flange 760F that includes one or more pass holes760H for a bolt (e.g. 731) that can be used to fix shape 760 to a unitor other fitting or structure. As seen from FIGS. 7S and 7T, shape 760may be fabricated or trimmed to any length including a short version(760S) having a single mounting hole 760H or a longer length (760L)having multiple such holes, in this case on the same centers as theplate 601 of unit 600B.

[0488]FIGS. 7U and 7T illustrate two variations.

[0489] In FIG. 7U (and as illustrated side elevation) in FIG. 7T anadditional pass hole 760HH is provided in the shape through thecenterline of the large opening 760O. When the tube or other shapeinserted in the large opening 760O of shape 760 has aligned pass holesof similar diameter a bolt 731E or a locking pin 732 can be insertedthrough the pass holes in both shape and tube, fixing the tube in place.The side elevation in FIG. 7T shows both pass holes 760H in the flange760 and the pass holes 760HH through the large opening.

[0490] Shape 760U has a flat surface 760I on which bolt heads can beardown.

[0491] Shape 760V in FIG. 7V omits the extended flange 760F of priorFigures where bolts through hole(s) 760HH will both retain a tube in theshape and the shape to the unit or other structure.

[0492]FIGS. 7W and 7X illustrate sections of such shapes in use. In theillustrated example, four sections of such shape (760A-D) are used tofix four lengths of tubing (200A-D) to a unit 600B. Note that inversionof the same shape (for example 760A versus 760C) allows offsetting thetubes they attach, such that the tubes will not conflict if extendedpast one another.

[0493] Other methods for attaching tubes and other shapes are possible.

[0494] Beginning at FIG. 8A are illustrated examples of how thecomponents illustrated in the previous Figures can be combined.

[0495] Among the purposes of such combinations is to create largerstructures including “pods” or self-contained structures that can beshipped in essentially their assembled state.

[0496]FIGS. 8A-8C are three views of a “pod” assembled from four units600B, tubing or pipe, and various fittings.

[0497] Referring to FIGS. 8A and 8B, two elevations located in FIG. 8C,sections of shape 760 (e.g. 760M and 760N) are used to attach lengths oftube (e.g. 200A and 200B) to a unit 600B. As seen in FIG. 8C, a planview, four such units 600B, one at each corner, are used with lengths oftube to assemble a rectangular framework, from which lighting fixturesand/or other loads could be hung, and which, in turn, can supportadditional structure, such as cross pipe 200I which, in turn, supportscross pipes 200J and 200K, which are attached by cheseboro or otherclamp.

[0498]FIGS. 8D-8F are similar views of a structure assembled from fourunits 600B and four sections of truss (including 400A and 400AA). Thatouter truss structure is illustrated as supporting additional internalstructure by means of tube attached to the trusses by cheseboros (e.g.tube 200L and clamp 230A).

[0499] One application for such components and such structures istemporary and touring uses, where important benefits are gained byminimizing the amount of assembly labor required on site to convert theequipment from the configuration in which it is used to theconfiguration in which it must be shipped.

[0500] In the case of the structures illustrated and others, so long asa structure or section of it is narrower in one dimension than the widthof the truck used to ship it, the structure or section, on the casters604 afforded by the unit 600B, can be rolled on and off the truckassembled.

[0501] To further reduce the amount of assembly labor at the point ofuse, a structure can be shipped with all or part of its “payload” in theform of lighting and/or scenic equipment attached. The height requiredby such equipment may exceed the “ground clearance” afforded by theheight of the unit 600B and, indeed, it may be desirable that asignificant portion of the lighting or scenic equipment extend below theplane of the bottom edge of unit 600B to minimize the obstruction itpresents.

[0502] Beginning at FIG. 6A is one method of providing additional“ground clearance” while preserving the ability to roll the structureinto place. In the Figures, a section of shape 740, here section 740X isbolted to one side of unit 600B in a vertical orientation. A caster 804is coupled with a tube 803 that extends into the large opening of shape740X, and can be maintained at a given distance below the bottom edge ofunit 600B by any one of several means, in this example, a bolt 731E thatextends through a pass hole in both shape 740X and tube 803. As seen inFIG. 8A, a plurality of such holes (e.g. 803H) can be provided in tube803 to permit fixing caster 804 at different distances from the bottomedge of unit 600B. By the use of a locking pin, like 732 of FIG. 7U,which can readily be removed, the height of the caster assembly can bechanged and the assembly quickly added or removed.

[0503] In the Figures, the extended caster assembly is also shown withan additional caster 814 that rotates around tube 803, and serves thepurpose of a fender that will prevent the structure from draggingagainst, for example, the sidewall of a truck.

[0504] Without such an extended caster assembly, structures locatingtheir units 600B in the same places will readily stack, by virtue oftheir stacking details like those illustrated in detail in FIG. 6U.

[0505] Beginning at FIG. 8G, it is illustrated that structures employingan extended caster assembly can also be stacked. Illustrated is a castercup 805 that receives and surrounds the large caster 804 of a structureabove it.

[0506] In the illustrated examples, the method used to increase “groundclearance” while preserving the ability to roll the structure is anextended caster assembly located on an exterior surface.

[0507] It will be apparent that such a structure could be located on oneof the two faces of unit 600B that are interior to the structure, whichwould permit increasing the size of caster cup 805 (as is illustrated inFIG. 8K) to reduce the tolerances required for capture of the largecasters of a structure above it.

[0508] It will be apparent that other methods of increasing “groundclearance”, such as structures similar to unit 600B of the same,different, or variable height and incorporating a compatible stackingdetail can be inserted between the units of a structure and each otherand the ground.

[0509] And it will be apparent that other methods of stacking unitsand/or structures including them are possible.

[0510]FIGS. 8K-8L illustrate another method of maintaining units in arelationship—in this case, a plate 660 which includes holes at spacingsthat hold two or more units 600B in the desired relationship (forexample, so as to fit between the side walls of a truck). The plate isbolted in place. Such a plate can, in fact, be accommodated between theplate 601 of a unit 600B and truss sections and/or shapes, adapters, andfittings. And it can be stiffened by forming or adding returns.

[0511] Alternatively, for example, as illustrated in FIG. 8M, two ormore sections of shape 760 or variations, in the appropriate length andwith the appropriate hole pattern at either end, will serve the purposeof maintaining two units at the desired distance.

[0512] In one application, larger structures or units of less than atruck-width and the desired length can be assembled; hung with thedesired lighting, scenic, and other elements; largely pre-cabled; andthen stacked for shipping as illustrated in FIG. 8N.

[0513] Upon arrival at the venue a stack is pushed or towed off thetruck to a location at which, as illustrated in FIG. 8O, a liftingmeans, for example chain motors like motor 65, are attached to the topunit. This may be the chain motors used to support that unit in itsdesired position. As illustrated in FIG. 8P, the top unit (here 60T) islifted off the stack, and the remaining units are rolled to the desiredlocation for the next unit in the stack, where the process is repeateruntil all units in the stack have been flown.

[0514] In an alternative, illustrated in FIG. 8Q, a means is providedfor linking the structures, such that lifting the top structure in astack will also lift those beneath it. In this alternative, the stack isbrought to an “unstacking” location where the top structure is attachedto a lifting method (such as chain motors). With the bottom structureand the structure immediately above it not linked, lifting the topstructure will lift all intermediate ones, including the one above thebottom structure. They are lifted clear of the bottom structure, whichcan be rolled away. The lifting method then lowers the structure thathad been above the bottom structure to the ground, allowing the linkbetween it and the structure above it (here 61 and 61A) to bedisconnected. The stack is lifted again, allowing the second structurefrom the bottom to be rolled away.

[0515] The process is repeated until all structures have been unstacked.

[0516] In both alternatives, the process is reversed to stack structuresfor shipping away from the point of use.

[0517] Such structures can travel with not only their lighting and/orscenic loads attached, but pre-wired. Indeed, because both lightingequipment and chain motors both require power, heretofore distributed inseparate systems, a bulk supply of electrical power can be provided toeach structure, which is there distributed for chain motors, un-dimmedpower supply, and dimmed power (via dimmers carried on the structure).Cable required to connect equipment on a structure with equipment atanother location can travel coiled atop the structure.

[0518]FIGS. 9R-9U illustrate one embodiment of another unit thatsimplifies the assembly of such larger structures that may travellargely assembled.

[0519] In the illustrated embodiment, elongated structural shapes (likemembers 812 and 813) are used to frame a generally rectangular structure80 having two ends, one illustrated in FIG. 8U, which can permit theattachment to various trusses and other structures. The length of thestructure (and hence the distance between the end plates 815 and 825)can be set at a distance less than the width of a transporting truck—forexample at 90″.

[0520] Like the units of the prior Figures, the unit 80 also providesfor attaching trusses and other structures and structural elements andshapes to form a larger, frequently rectangular structure. Referring toFIG. 8RR, holes like 820 are provided in a pattern that permits the useof trusses of varying size and, in the case of smaller trusses,alignment. (The dotted outline 826 is of “20.5″” truss.) In theillustrated embodiment, those holes 820 are provided in either the mainchords (e.g. 812 and 813) or in intermediate members like 817 and 818.In the illustrated embodiment, a section of structural angle 816 is usedto reinforce the corner and a piece of plate 818 to reinforce theside—the very extensive interfaces between the various. structuralcomponents resulting in considerable strength.

[0521] Referring to other views, the unit 80 also includes a pair ofstructural angles 821 and 822 used to provide a point of attachment forlifting the unit; for a generally circular tube 823 extending under theunit 80 for supporting additional loads; and for structuralreinforcement. The unit is casters for handling and ground clearance canbe increased by various methods including those illustrated in priorFigures.

[0522] Prior figures have illustrate methods by which unit 600B andstructures can be equipped with casters.

[0523]FIGS. 9A-9Q illustrate methods by which trusses themselves notprovided with integral casters can be provided with casters whendesired.

[0524] Beginning at FIG. 9A is illustrated some of the possibleembodiments of a “wheel bracket” that can be attached to a section oftruss or similar structure.

[0525]FIG. 9A is s side elevation of “wheel bracket” 901, showing itsside face 903 and casters 904 and 905. FIG. 9C is a cross section fromthe same perspective, showing the horizontal internal member 902 towhich the casters 904 and 905 are mounted, as well as the parts 907 and908 that engage the truss chords.

[0526]FIG. 9I is a detailed view of the latch mechanism that retains thewheel bracket on a truss section. A known mechanism, it includes twoshapes 908 and 909 that rotate around respective pivots 908P and 909P.In the “engaged” position the concave side of part 908 conforms to theexterior profile of a truss chord. A tab on part 908 resting on a shelfon part 909 prevents rotation of portion 908A of part 908 away from thetruss chord, which would release the latter. The curved shoulder 903Aand projection 903B of the side face 903 of the bracket in which parts908 and 909 are mounted prevent the chord from rotating part 908 towardsits portion 908B. The bracket is thus retained on the truss chord.

[0527] The illustrated mechanism is hardly the only method of retentionand many alternatives are possible.

[0528] To release the truss chord the user presses a lever 909L formedin part 909 against spring 919 releasing the pawl mechanism at theinterface between parts 908 and 909, permitting the former to rotate,releasing the truss chord and permitting the removal of the bracket fromthe truss. Part 908 is held in this “open” position by its associatedspring 918, with its portion 908B extending into the area occupied bythe truss chord in the “engaged” position (as is seen in FIG. 9B. Part907, which engages the other chord of the truss, can be produced, inthis embodiment, by another section of the shape used for part 908, thispart fixed in relation to the bracket and truss.

[0529] As illustrated in FIG. 9B, the user attaches the wheel bracket toa truss section by fitting the fixed side 907 over one chord of thetruss, rotating the bracket 901 around that chord until portion 908B ofpart 908 comes in contact with the upper chord of the other truss chord.Continued rotation of the bracket towards that other chord results inthe truss chord pressing against portion 908B of part 908, causing it torotate about its pivot until this other truss chord is seated againstthe recess 903A and projection 903B of the bracket's side panel 903, andthe latch mechanism between the two parts locks.

[0530] As seen in FIG. 9A, the side panel 903 of bracket 901 has arecess for the truss chords both above (903A) and below (903C) theprojection (903B) such that, as seen in FIG. 9D, one section of trusswith a wheel bracket 901 attached to its chords (here 403 and 404) canbe stacked on another. Not only do the casters 904 and 905 on the wheelbracket fall within the chords (here 401L and 402L) of the lower truss,but the recess (903C) in the side panel of the wheel bracket locks thetwo trusses in alignment.

[0531]FIG. 9E is an end elevation of the wheel bracket seen in the priorFigures from the latch end. FIG. 9F is a detail of an H-shaped member(for example, an extrusion) that can be used for its structure. FIG. 9Gillustrates a member created from two U-shared parts (which might befabricated from sheet metal), in this example, held together using thesame bolts used to mount the casters (e.g. 904).

[0532]FIG. 9J is a variation, bracket 901C, whose structure provides arecess that allows its use with the “compound” truss illustrated in FIG.4D by avoiding interference with the additional truss chords 403C and404CC.

[0533]FIG. 9K is another variant in which separate side panels (e.g.903D) are illustrated as is a central member that allows changing thewidth of the bracket, allowing adjustment to different truss chordspacings, and therefore, different truss designs.

[0534]FIGS. 9L and 9M illustrate another variant that permits suspendingthe truss a bracket also serving as a wheel bracket. In the illustratedembodiment, the sides 903C are extend upwards and provided with passholes (920A-920E) for attachment to lifting means.

[0535]FIG. 9N is a side elevation and FIG. 9O an end elevation ofanother embodiment of a wheel bracket, in this case assembled from flatplate and generally rectangular tubing.

[0536] A pair of tubes 911 and 916 are used as a platform to support thetruss via the casters 904 and 905 bolted to it. Plates 914 and 915 areused to align the bracket between the lower main chords 403 and 404 ofthe truss section to which it is attached and, when stacked, with theupper chords 401L and 402L of the truss below it. A third tube 912 isretained between plates 914 and 915 by bolts, locking pins (like 916) orother means, those portions extending over truss chords 403 and 404retaining the wheel bracket to the truss.

[0537] When multiple trusses are stacked, the height of the stackrelative to its width can make it unstable. The Figures illustrate onemethod of improving stability—by linking two stacks. Tubular member 913is a loose fit within member 912 and, as illustrated in FIG. 9N, can beextended beyond the tube 912 of one bracket to be inserted into the tube912 on an adjacent bracket, where it is retained by locking pins throughboth, linking the two brackets and therefore their stacks. FIG. 9Willustrates two sets of such paired stacks in a truck.

[0538]FIGS. 9P and 9Q illustrate another variation that includes a wheelbracket and provisions to lift the truss section with a chain motor thattravels internal to the truss.

[0539] Referring to the Figures the elements in common with the bracketin the prior Figures will be seen. The side panels (e.g. 914A) have beenextended upwards and formed with or provided with a right-angle shapeaffording a horizontal surface upon which a chain motor 650 can sit,cushioned by padding 924. The chain motor's hook extends between the twoside panels and a locking pin or other part is inserted through holes(e.g. 920B) in the side panels to form the lifting point for the hook.

[0540] The motor is contained completely within the truss section forshipping and can be readily “floated” above the truss for use by thesimple expedient of removing the pin. It will be recognized that theunit 80 of FIGS. 8R-8V incorporates a similar detail in the form ofangles 821 and 822 with their pass holes and the internal members (e.g.827) that can serve as a shelf to support the chain motor.

[0541]FIG. 9P is a side elevation and FIG. 9Q an end elevation ofanother embodiment that supports a chain motor inside the truss.

[0542] In this case, the embodiment is assembled from webbing andheavy-duty fabric.

[0543] Referring to the Figures, a “bag” of heavy-duty fabric isfabricated, which may have a reinforcing rim 954 to maintain the shapeof its mouth opening. That bag is hung from the upper chords 401 and 402of a truss by means of webbing straps that wrap the truss chord and canbe closed by snap hooks (e.g. 952) to “D”-rings (e.g. 953); by buckles;or other means. The strap detail includes straps (e.g. 955) upon whichthe chain motor can sit, keeping it from resting on (or being coveredby) the motor chain which collects in the bottom 957 of the “bag” below.The motor need not be attached to the “bag”—allowing the motor to risefrom a shipping position 650S to a higher “use” position 650E, to permitbridling that increases the stability of the truss and permits the useof horizontal safety lines. Holes (e.g. 958) may be provided for bridlesto the lower chords and more typical bridles that wrap both the lowerand upper chords can travel attached.

[0544] A similar approach can be taken using hard materials. FIG. 9T isa section; FIG. 9U a plan view; and 9V a side elevation usingsubstantially rigid materials. The “bag” might be, for example, formedfrom plastic. The “shelf” supporting the motor in transit 965, might beof the same or a heavier material—for example, from aluminum.

[0545] When an un-castered truss section is stacked on another, there istypically nothing that prevents one section from moving with respect tothe other, with undesirable consequences including collapsing stacks oftruss, increased difficulty in packing trusses on a truck or in astorage space, and pinching the hands of those handling the trusssections. Such shifting is common when several trusses are stacked andthe stack placed on wheels.

[0546] The wheel brackets of prior Figures illustrate provisions toprevent trusses from shifting relative to one another.

[0547]FIGS. 9X-9Z illustrate one design for a simple and inexpensivepart for the sole purpose of preventing undesirable movement betweenstacked trusses.

[0548] The embodiment illustrated is for those trusses having crossbraces between major chords on two opposing faces, those cross bracesintersecting the major chord at right angles (“ladder” or “rung”braces).

[0549]FIG. 9Y is a section through both “rung” cross braces (410 and410L) of two stacked trusses. “Stacker” 930 is an H-shaped extrusion ofmetal or plastic (or is formed by another other method of fabrication)that provides a recess for each of the two “rung” cross braces of a pairof trusses stacked. As seen from FIG. 9X a section through the trussstack that is a side elevation of the “stacker” in use (and seen indetail in FIG. 9XX) the vertical sides (e.g. 933) of the “stacker” arecut or formed to the general contour of the main truss chords that the“rung” cross braces intersect. In a manner similar to the “wheelbracket”, the two trusses are prevented from moving laterally withrespect to each other.

[0550] It will be appreciated that, absent other provisions, one trusswill remain able to move along the elongated axis of the two, rotatingthe shape of “stacker” 930 around one of the “rung”cross braces. Toprevent this, the horizontal portion 932 of the “stacker” shape 930extends between the two main chords, the projection tab (e.g. 932A)sandwiched in place by the weight of the upper truss section(s), suchthat the “stacker” cannot be easily rotated around the “rung” crossbrace. This extension is visible in FIG. 9XX and in partial plan viewFIG. 9Z.

[0551] In many applications, structures formed from trusses and fromcombinations of structural shapes and fitting are “flown” above theground by lifting methods.

[0552] One of the most common such methods is the use of a “chainmotor”.

[0553] Generally, the hook attached to the free end of the chain passingthrough the motor is attached to the building or other structure above.The hoist motor, which is electrically-powered, is run, pulling excesschain through the motor until the motor begins to pull itself up thechain towards the point of attachment. The motor is paused withinseveral feet of the load so that various other components, includingknown “spansets”, steel wire rope, and shackles can be used to connectthe motor body with the load. Once the load has been attached to themotor body, the motor can then be used to lift the load, continuing itsclimb up the chain. FIG. 6J has illustrated a truss structure supportedby chain motor 650 via a “bridle” 656 of steel wire rope.

[0554] Generally, chain motors are shipped in roadcases, one or two percase. Each time the structure is “flown”, roadcases containing themotors (one hundred or more on a large production) must be maneuveredinto the approximate location at which they will be required. A numberof operations are required to remove each motor from its roadcase;assemble the required spansets, wire rope, shackles, and other parts;correctly attach them and the motor to the load; “fly” the combination;and store the roadcases for later use.

[0555] Beginning at FIG. 10A are illustrate various improvements thatdramatically reduce the effort required to “fly” a structure.

[0556] Refer now to FIG. 10A a cross section through a unit 600B with achain motor 650 visible above. It is apparent from the Figure that thereis sufficient space in unit 600B to accommodate chain motor 650 forshipping. As chain motors are frequently used at or near “corner cubes”and similar elements, it is probable that anywhere a unit 600B isemployed a chain motor will be required. Shipping a chain motor in theunit 600B eliminates the requirement to provide or handle a separateroadcase for the motor.

[0557]FIGS. 10A and 10B illustrate provisions in unit 600B to attachchain motor 650 to it. As will be seen in detail in FIGS. 10I and 10J, abracket 620 that accepts a locking pin 622 that is engaged by the hook650H of chain motor 650, providing a direct connection between the chainmotor 650 and unit 600B. As illustrated in FIG. 10C, the unit 600B canbe bolted or otherwise attached in a span of truss sections and/or attheir intersection and/or in a structure like that illustrated in FIG.8A-8?. A chain motor is shipped in the unit 600B and arrives alreadyattached to it.

[0558] Installing a unit 600B in a span of truss sections with the chainmotor internal is not always practical for two reasons.

[0559] One is that the “point” at which a chain motor can be located(due, for example, to the design of a building's structure) may notalign with the truss or other structure flown from it, such that thechain motor in a unit 600B inserted in that structure will align withit.

[0560]FIGS. 10D and 10E illustrate an alternative for such situations,in which the chain motor 650 still travels and works attached to theunit 600B, but the truss or other structure is suspended below it, hereby bridle legs 656A and 656B attached to the bracket 620 of unit 600B bylocking pins 657A and 657B. It will be apparent that there aresubstantial savings in the time and labor required with completeflexibility of location.

[0561] Another reason limiting the universal application of the modeillustrated in FIGS. 10B and 10C is that when a truss or structure issupported from “points” all on a common line, there is a tendency forthat truss or structure to roll about its long axis, which is magnifiedwhen the truss or structure is supported from a point (in this case,motor hook 650H) that is as close to the center-of-gravity as when themotor is contained within the cross section of the truss.

[0562] The mode of FIGS. 10D and 10E also raises the lifting pointsufficiently above the illustrated truss to improve stability. FIGS. 10Fand 10G illustrate another mode in which the unit 600B remains in thestructure, while the motor and its associated lifting point are raisedsignificantly above it.

[0563]FIGS. 6H-6J illustrate some of the possible designs for a bracketassembly suited to the illustrated modes.

[0564]FIG. 10H is a cross section through unit 600B showing thepreviously illustrated side plate 601, upper edge shape 611, and loweredge shape 612. A structural shape or shapes is used to form a bracketassembly 620 having upper flanges (e.g. 620J) that include pass holes620A-E that receive parts, for example, locking pin 622 to which hook650H of chain motor 650 can attach as well as locking pins 657A and 657Bthat attach the legs of a bridle from a chain motor or other supportabove. The shape or shapes also include lower flanges (e.g. 620K) thatprovide pass holes for suspending loads below. The shape or shapes alsohave horizontal flanges (e.g. 620F) that bear up under lower edge shape612, transferring the load from the unit 600B to the chain motor 650.

[0565] Different embodiments of the bracket assembly are illustrated inFIGS. 10I and 10J, differing in the design of the lower flange 620K,which, in the case of the embodiment of FIG. 10J, permits the directattachment of shackles (e.g. 655A).

[0566] It can be desirable that the spacial relationship between thechain motor and the load it supports be varied to account for variationsin truss center of gravity produced by asymmetrical loading.

[0567] Various prior Figures provide for such variation by offeringmultiple points of attachment (as well as the option of bridles withlegs of unequal length. FIG. 10K is a detailed sectional viewillustrating a provision for shifting the attachment point in a secondaxis—by employing a “tongue in groove” connection between the attachmentflange 620 (and specifically a flange 620F formed from its horizontalportion) and a groove formed in the unit's framework (for example, inthe extrusion used at the unit's lower edge.

[0568]FIGS. 10L, 10M, and 10O illustrate an embodiment in which thechain motor 650A is provided with a lifting plate rather than hook (asis the case with Chainmaster brand). In this case a larger lifting plate651 can be employed that is captive to the motor, the motor attached tothe unit 600B by means of a fastener (e.g. 622 or 622A) that links thelifting plate with the unit via holes like 651B in the lifting plate and620B in bracket 620J. The lifting plate 651 extends through the bottomof unit 600B, such that loads hung below the unit are attached directlyto the lifting plate, and the offset “ears” with holes 651A and 651Eallow travelling the motor with an internal bridge attached.

[0569] There are many methods of supporting the motor within the unit,which should not be understood as limited. FIG. 8S and FIG. 9Pillustrate simple “shelves” or internal members on which the motor canride in transit; soft webbing straps have been illustrated; and FIG. 10Nshows a internal divider.

[0570] It may also be desirable to cover the unit in shipping to preventdirt, rain, and debris from entering, as well as to permit the unit tobe flipped off its wheels or other equipment placed atop it.

[0571]FIG. 10P shows a simple formed cover 670A that drops or hingesover the unit 600B, which can be provided with latches (e.g. 671) toretain it in place. The top edge extrusion has been modified with alower lip for the latch to engage.

[0572]FIG. 10Q shows a flat cover 670B, which again, may be retained bylatches. The casters (e.g. 604U) of a unit or roadcase are captivated bythe well formed by top edge extrusion 611L.

[0573]FIG. 10R shows another flat cover 670C, retained on one side by adetail in the top edge extrusion 611K and on the other by latch 671.

[0574] Beginning at FIG. 11A are other approaches to improvingefficiency by permitting trusses to be shipped with loads attached.

[0575]FIG. 11A is a side elevation of two truss sections 40A and 40B,joined via a leg assembly 860, whose legs (e.g. 864) support the trussesat a distance sufficiently above the ground to permit lighting fixtures(e.g. fixture 50) to be hung. The legs are equipped with casters (e.g.865) permitting the trusses to be rolled on and off trucks and betweenthe truck and their point of use in a venue.

[0576] FIGS. 11A-D illustrate the design and operation of thisembodiment. Two plates 861 and 861A are spaced apart, here by astructural shape 868, to produce a clearance between their adjoiningfaces slightly greater than the structural shape used for legs 864 and864A. Pass holes aligned with the joining holes for the truss sectionsare provided through both plates 861 and 861A and any structural shapeused between them. By the simple expedient of the use of longer bolts(e.g. 510), the pair of plates 861 and 861A are sandwiched between thetwo truss sections 40A and 40B. The legs, which are connected by brace866, are fixed by locking pins (e.g. 867) inserted through pass holes inboth the plates and the legs. At least two sets of pass holes areprovided: one set with the legs in an extended position (as illustratedin FIG. 11B; and another set for a retracted position (shown in FIG.11C). The truss sections (with their loads attached) are rolled intoposition, and, once supported by lifts or chain motors and weight isremoved from the legs and wheels, the locking pins are removed and thelegs are either removed entirely or moved to the retracted position.

[0577] Leg assemblies can be inserted at any joint between trusssections and at truss ends and, as illustrated in FIG. 11E, trusses canbe shipped pre-hung with fixtures and pre-cabled in lengths limited onlyby the size of truck employed in shipping.

[0578]FIG. 11F illustrates another embodiment in which a single plate isused and the leg retained in an offset structural shape 862.

[0579]FIGS. 11G-11I illustrate another embodiment using a single plate861 and dual legs. A bracket 869 connects the two legs with each otherand cross-brace 866 and provides a surface for mounting a caster 865Avia a plate rather than a post.

[0580]FIG. 11J illustrates that an alternative shape 861C for the platecan incorporate a detail that supports and engages a truss above forshipping, and FIG. 11K shows that nine truss sections can beaccommodated in a typical truck in this manner.

[0581]FIGS. 11L and 11M illustrate an alternative method of attachmentto a truss—brackets 870 and 870A can be clamped to the main chords ofthe truss using cheseboros (e.g. 872). U-shaped channel 871 accepts leg864, which is retained by locking pin 867 in a manner similar to priorembodiments.

[0582]FIGS. 8N and 8O illustrate a method of shipping a chain motor witha truss that is too large to fit within it.

[0583] In one embodiment of this “motor saddle” 830, two plates orpanels 831 and 832 are held in a parallel, spaced-apart relationship,here by standoffs 833 and 834, their overall dimension being less thanthe clearance between the structural members on the top side of a truss,here “rungs” 410U and 410UA. As will be seen from FIG. 11O, the externalprofile of the plates has a lower portion 832C less than the clearancebetween the two upper main chords 401 and 402 and a central portion 832Bwider than that clearance, such that the plate sits atop the upper trusschords 401 and 402. The upper edge of the plate has a recess 832A thataccepts a chain motor 650. The embodiment also illustrates a bag or bin836 for the motor's chain. In this embodiment, the bag or bin issuspended using a readily removeable locking pin 835 so that the motorsaddle 830 can be located with side panels 831 and 832 straddling atruss member such as 410U for greater flexibility in location.

[0584] It will be apparent that such a motor can travel with known“spansets” wrapped around the truss chords and attached to the chainmotor, such that no additional operations are required before the motorcan lift the truss. It will also be apparent that the motor will readilylift itself out of recess 632A, such that the motor will put the“spansets” under load and can assume a position significantly above itsshipping position, increasing the stability of the truss and allowingfor a horizontal safety line.

[0585] In this and other cases, an improved technique can be used toassure that chain from the motor reaches a bag or bin—a rigid orflexible tube or hose through which the chain travels can connect itsexit port on the motor housing and the storage bag or bin.

[0586] With an externally-carried chain motor, an additional suction oftruss cannot be readily stacked atop. FIGS. 11P and 11Q illustrate onepossible design for a “stacker”. Composed, like the “motor saddle” ofthe prior Figures, of two plates 841 and 842, maintained in a parallel,spaced-apart relationship by standoffs (e.g. 843) or other means.

[0587] Like the “motor saddle” 830, stacker 840 has a lower portion thatfits between the two top chords of a truss 410L and 402L; an upperportion that fits between the two bottom chords 403U and 404U of a trussabove; and a middle portion wider than both. As a result, when insertedin the top of a truss, a second truss can be stacked atop it, with avertical clearance between the two maintained sufficient for a motorcarried in a “saddle” or for other purposes.

[0588]FIG. 11R is a side elevation illustrating both a “motor saddle”830 and a stacker 840 in use, FIG. 11S being an end elevation of theiruse in a truck.

[0589] Where previous Figures have shown only a single level of trussesusing the leg assembly and pre-hung fixtures, multiple levels arepossible. In such cases, in one example, the cross-brace 866 of the legassembly on the upper truss can rest atop the lower truss, the twotrusses offset slightly to prevent interference between the wheels ofthe upper truss and the leg bracket assembly of the lower one. FIG. 11Tillustrates a variation in the leg assembly that offsets the wheelsoutwards to increase stability of the stack and to eliminateinterference between the leg assemblies of the two levels.

[0590]FIG. 11U illustrates a flat plate that may be bolted between trusssections, with or without a leg assembly,that provides a recess forsupporting another truss section above it in shipping.

[0591]FIG. 11V is a section showing an linear extruded hinge such asproduced as the “Roton” brand by Hager Hinge used in a truss or otherstructure design in which portions are moveable between a one andanother position. Hinge 90 includes two leaf extrusions 90B and 90D thatinterlock with a third extrusion 90C as a cover.

[0592] While many designs are possible, the embodiment illustratedprovides channels such as 90E in leaf 90B that accepts other structuralshapes, such as member 92 in a manner equivalent to the techniqueillustrated in FIG. 4S-4V.

[0593]FIG. 11W illustrates the hinge opened.

[0594]FIG. 11X illustrates another extrusion 93 used to close the openchannel.

[0595]FIGS. 12G-12I illustrate a method of mounting the clamps used toattach fixtures to trusses in a manner that eliminates the need toattach and remove them from the fixture either when converting betweenhung and floor use, or to reduce height for accommodation in roadcases.

[0596] A clamp such as 59 is attached to a bracket or other means whichis attached to the fixture so as to permit its rotation between a stowedposition parallel to the bottom surface of the fixture enclosure 50E (asillustrated in FIG. 12I) and an extended position in which the clamp isused to hang the fixture (seen in FIG. 12G and 12H), here illustrated as(but not limited to) a bracket 53, pivotally mounted via pivot 52, toanother bracket 51, attached to the fixture enclosure 50E by bolts (e.g.55). Preferably the clamp 59 is also attached to permit rotation aboutits central axis 59A—for example, as seen in the difference between FIG.12G and 12H to accommodate different relationships between the fixtureand the members from which it is hung.

[0597]FIG. 12I also illustrates a pass hole 51H in the bracket to permitaccess to the bolt 55 used to mount bracket 51 to the fixture enclosureand feet (e.g. 56) for the floor mode.

[0598] In these, as in all other cases, variations and other embodimentsare possible within the scope of the inventions, which should not beunderstood as limited except by the claims.

What is claimed is:
 1. In a structure for the support of loads: aplurality of elongated structural shapes, said structural shapesdisposed in a substantially parallel relationship; members mechanicallyconnected to and between said elongated structural shapes formaintaining said substantially parallel relationship; said elongatedstructural shapes and members forming a substantially rigid structuralunit capable of supporting loads; said structural unit providing forend-wise connection of a plurality of such units to form a load-bearingstructure of greater length than a single such unit; said elongatedstructural shapes having a cross section that is substantially a polygonhaving eight or more sides.